Flatulence is the expulsion through the
rectumThe rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
of a mixture of gases that are byproducts of the digestion process of
mammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s and other animals. The medical term for the mixture of gases is
flatus, informally known as a
fart, or simply (in
American EnglishAmerican English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....
)
gas. The gases are expelled from the rectum in a process colloquially referred to as "passing gas", "breaking wind" or "
fartFart is an English language vulgarism most commonly used in reference to flatulence. The word "fart" is generally considered unsuitable in a formal environment by modern English speakers, and it may be considered vulgar or offensive in some situations. Fart can be used as a noun or a verb...
ing". Flatus is brought to the rectum by the same
peristalticPeristalsis is a radially symmetrical contraction and relaxation of muscles which propagates in a wave down the muscular tube, in an anterograde fashion. In humans, peristalsis is found in the contraction of smooth muscles to propel contents through the digestive tract. Earthworms use a similar...
process which causes feces to descend from the large intestine. The
noiseIn common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...
s commonly associated with flatulence are caused by the
vibrationOscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...
of the
analThe anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
sphincterA sphincter is an anatomical structure, or a circular muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning...
, and occasionally by the closed
buttocksThe buttocks are two rounded portions of the anatomy, located on the posterior of the pelvic region of apes and humans, and many other bipeds or quadrupeds, and comprise a layer of fat superimposed on the gluteus maximus and gluteus medius muscles. Physiologically, the buttocks enable weight to...
.
Composition
NitrogenNitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
, the main constituent of air, is the primary
gasGas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
released during flatulence, along with
carbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
. The lesser component gases
methaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
and
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
are flammable, and so flatus containing adequate amounts of these can be
ignitedFart lightning or pyroflatulence is the practice of igniting the gases produced by human flatulence, often producing a flame of a blue hue, hence the act being known colloquially as a "blue angel", or in Australia, a "blue flame". The fact that flatus is flammable, and the actual combustion of it...
. However, not all humans produce flatus that contains methane. For example, in one study of the
fecesFeces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
of nine adults, only five of the samples contained
archaeaThe Archaea are a group of single-celled microorganisms. A single individual or species from this domain is called an archaeon...
capable of producing methane. Similar results are found in samples of gas obtained from within the rectum.
The gas released during a flatus event frequently has an unpleasant odor. For many years, this was thought to be due to
skatoleSkatole or 3-methylindole is a mildly toxic white crystalline organic compound belonging to the indole family. It occurs naturally in feces and coal tar, and has a strong fecal odor...
and
indoleIndole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. Indole is a popular component of fragrances and the precursor to many pharmaceuticals. Compounds that contain an...
, which are byproducts of the
digestionDigestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....
of
meatMeat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...
. However, gas chromatography testing in 1984 revealed that
sulfurSulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
-containing compounds, such as
methanethiolMethanethiol is a colorless gas with a smell like rotten cabbage. It is a natural substance found in the blood and brain of humans and other animal as well as plant tissues. It is disposed of through animal feces. It occurs naturally in certain foods, such as some nuts and cheese...
,
hydrogen sulfideHydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...
(rotten egg smell) and
dimethyl sulfideDimethyl sulfide or methylthiomethane is an organosulfur compound with the formula 2S. Dimethyl sulfide is a water-insoluble flammable liquid that boils at and has a characteristic disagreeable odor. It is a component of the smell produced from cooking of certain vegetables, notably maize,...
, were also responsible for the smell.
The incidence of odoriferous compounds in flatulence emissions increases from herbivores, such as
cattleCattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
, through omnivores to carnivorous
speciesIn biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
. Such odor can also be caused by the presence of large numbers of microflora
bacteriaBacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
and/or the presence of feces in the rectum.
The major components of the flatus, which are odorless, by percentage are:
- Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
: 20–90%
- Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
: 0–50%
- Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
: 10–30%
- Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
: 0–10%
- Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
: 0–10%
Physiology
Flatus is brought to the rectum by the same process which causes
fecesFeces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
to descend from the large intestine (see
peristaltic movementPeristalsis is a radially symmetrical contraction and relaxation of muscles which propagates in a wave down the muscular tube, in an anterograde fashion. In humans, peristalsis is found in the contraction of smooth muscles to propel contents through the digestive tract. Earthworms use a similar...
), and may cause a similar feeling of urgency and discomfort. Researchers investigating the role of sensory nerve endings in the anal canal did not find them to be essential for retaining fluids in the anus, and instead speculate that their role may be to distinguish between flatus and feces, thereby helping detect a need to defecate or to signal the end of defecation.
The sound varies depending on the tightness of the sphincter
muscleMuscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
and
velocityIn physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant ...
of the
gasGas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
being propelled, as well as other factors, such as water and body fat. The auditory pitch (sound) of the flatulence outburst can also be affected by the anal
embouchureThe embouchure is the use of facial muscles and the shaping of the lips to the mouthpiece of woodwind instruments or the mouthpiece of the brass instruments.The word is of French origin and is related to the root bouche , 'mouth'....
. Among humans, flatulence occasionally happens accidentally, such as incidentally to
coughA cough is a sudden and often repetitively occurring reflex which helps to clear the large breathing passages from secretions, irritants, foreign particles and microbes...
ing or sneezing or during
orgasmOrgasm is the peak of the plateau phase of the sexual response cycle, characterized by an intense sensation of pleasure...
; on other occasions, flatulence can be voluntarily elicited by tensing the rectum or "bearing down" on stomach or bowel muscles and subsequently relaxing the anal sphincter, resulting in the expulsion of flatus.
Causes
Intestinal gas is composed of varying quantities of exogenous sources (air that is ingested through the nose and mouth) and endogenous sources (gas produced within the digestive tract). The exogenous gases are swallowed (
aerophagiaAerophagia is a condition that occurs when a person swallows too much air, which goes to the stomach. It causes abdominal bloating and frequent belching and may cause pain.-Causes:...
) when eating or drinking or increased swallowing during times of excessive salivation (as might occur when nauseated or as the result of gastroesophageal reflux disease). The
endogenousEndogenous substances are those that originate from within an organism, tissue, or cell. Endogenous retroviruses are caused by ancient infections of germ cells in humans, mammals and other vertebrates...
gases are produced either as a by-product of digesting certain types of food, or of incomplete
digestionDigestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....
. Anything that causes food to be incompletely digested by the
stomachThe stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
and/or
small intestineThe small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
may cause flatulence when the material arrives in the large intestine, due to
fermentationFermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
by
yeastYeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
or prokaryotes normally or abnormally present in the
gastrointestinal tractThe human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
.
Flatulence-producing foods are typically high in certain
polysaccharidePolysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
s, (especially oligosaccharides such as
inulinInulins are a group of naturally occurring polysaccharides produced by many types of plants. They belong to a class of fibers known as fructans. Inulin is used by some plants as a means of storing energy and is typically found in roots or rhizomes...
). Those foods include
beanBean is a common name for large plant seeds of several genera of the family Fabaceae used for human food or animal feed....
s,
lentilThe lentil is an edible pulse. It is a bushy annual plant of the legume family, grown for its lens-shaped seeds...
s,
dairy productDairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...
s,
onionThe onion , also known as the bulb onion, common onion and garden onion, is the most widely cultivated species of the genus Allium. The genus Allium also contains a number of other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion The onion...
s,
garlicAllium sativum, commonly known as garlic, is a species in the onion genus, Allium. Its close relatives include the onion, shallot, leek, chive, and rakkyo. Dating back over 6,000 years, garlic is native to central Asia, and has long been a staple in the Mediterranean region, as well as a frequent...
,
scallionScallions , are the edible plants of various Allium species, all of which are "onion-like", having hollow green leaves and lacking a fully developed root bulb.-Etymology:The words...
s,
leekThe leek, Allium ampeloprasum var. porrum , also sometimes known as Allium porrum, is a vegetable which belongs, along with the onion and garlic, to family Amaryllidaceae, subfamily Allioideae...
s,
turnipThe turnip or white turnip is a root vegetable commonly grown in temperate climates worldwide for its white, bulbous taproot. Small, tender varieties are grown for human consumption, while larger varieties are grown as feed for livestock...
s, rutabagas,
radishThe radish is an edible root vegetable of the Brassicaceae family that was domesticated in Europe, in pre-Roman times. They are grown and consumed throughout the world. Radishes have numerous varieties, varying in size, color and duration of required cultivation time...
es,
sweet potatoThe sweet potato is a dicotyledonous plant that belongs to the family Convolvulaceae. Its large, starchy, sweet-tasting, tuberous roots are an important root vegetable. The young leaves and shoots are sometimes eaten as greens. Of the approximately 50 genera and more than 1,000 species of...
es, potatoes,
cashewThe cashew is a tree in the family Anacardiaceae. Its English name derives from the Portuguese name for the fruit of the cashew tree, caju, which in turn derives from the indigenous Tupi name, acajú. It is now widely grown in tropical climates for its cashew nuts and cashew apples.-Etymology:The...
s,
Jerusalem artichokeThe Jerusalem artichoke , also called the sunroot, sunchoke, earth apple or topinambour, is a species of sunflower native to eastern North America, and found from Eastern Canada and Maine west to North Dakota, and south to northern Florida and Texas...
s,
oatThe common oat is a species of cereal grain grown for its seed, which is known by the same name . While oats are suitable for human consumption as oatmeal and rolled oats, one of the most common uses is as livestock feed...
s,
wheatWheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
, and
yeastYeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
in
breadBread is a staple food prepared by cooking a dough of flour and water and often additional ingredients. Doughs are usually baked, but in some cuisines breads are steamed , fried , or baked on an unoiled frying pan . It may be leavened or unleavened...
s.
CauliflowerCauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed...
,
broccoliBroccoli is a plant in the cabbage family, whose large flower head is used as a vegetable.-General:The word broccoli, from the Italian plural of , refers to "the flowering top of a cabbage"....
,
cabbageCabbage is a popular cultivar of the species Brassica oleracea Linne of the Family Brassicaceae and is a leafy green vegetable...
, Brussels sprouts and other
cruciferous vegetablesVegetables of the family Brassicaceae are called cruciferous vegetables. The vegetables are widely cultivated, with many genera, species, and cultivars being raised for food production such as cauliflower, cabbage, cress, bok choy, broccoli and similar green leaf vegetables...
that belong to the genus
BrassicaBrassica is a genus of plants in the mustard family . The members of the genus may be collectively known either as cabbages, or as mustards...
are commonly reputed to not only increase flatulence, but to increase the pungency of the flatus.
In beans, endogenous gases seem to arise from complex oligosaccharides (
carbohydrateA carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
s) that are particularly resistant to digestion by mammals, but which are readily digestible by
gut floraGut flora consists of microorganisms that live in the digestive tracts of animals and is the largest reservoir of human flora. In this context, gut is synonymous with intestinal, and flora with microbiota and microflora....
– microorganisms (methane-producing archaea;
Methanobrevibacter smithiiMethanobrevibacter smithii is the dominant archaeon in the human gut. It is important for the efficient digestion of polysaccharides because it consumes end products of bacterial fermentation. Methanobrevibacter smithii is a single-celled micro-organism from the Archaea domain. M...
) that inhabit the digestive tract. These oligosaccharides pass through the upper intestine largely unchanged, and when they reach the lower intestine,
bacteriaBacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
feed on them, producing copious amounts of flatus.
In the case of people who have
lactose intoleranceLactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk...
, intestinal bacteria feeding on lactose can give rise to excessive gas production when
milkMilk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...
or lactose-containing substances have been consumed.
Interest in the causes of flatulence was spurred by high-altitude
flightFlight is the process by which an object moves either through an atmosphere or beyond it by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement....
and the space program; the low
atmospheric pressureAtmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
, confined conditions, and stresses peculiar to those endeavours were cause for concern. In the field of mountaineering, the phenomena of
high altitude flatus expulsionHigh altitude flatus expulsion is a gastrointestinal syndrome which involves the spontaneous passage of increased quantities of rectal gases at high altitudes. First described by Joseph Hamel in c...
was first recorded over two hundred years ago.
Some infections, such as
giardiasisGiardiasis or beaver fever in humans is a diarrheal infection of the small intestine by a single-celled organism Giardia lamblia. Giardiasis occurs worldwide with a prevalence of 20–30% in developing countries. In the U.S., 20,000 cases are reported to the CDC annually, but the true annual...
, are also associated with flatulence.
Dietary
Certain
spiceA spice is a dried seed, fruit, root, bark, or vegetative substance used in nutritionally insignificant quantities as a food additive for flavor, color, or as a preservative that kills harmful bacteria or prevents their growth. It may be used to flavour a dish or to hide other flavours...
s have been reported to counteract the production of intestinal gas, most notably the closely related
cuminCumin is a flowering plant in the family Apiaceae, native from the east Mediterranean to India. Its seeds are used in the cuisines of many different cultures, in both whole and ground form.-Etymology:...
,
corianderCoriander is an annual herb in the family Apiaceae. Coriander is native to southern Europe and North Africa to southwestern Asia. It is a soft, hairless plant growing to tall. The leaves are variable in shape, broadly lobed at the base of the plant, and slender and feathery higher on the...
,
carawayCaraway also known as meridian fennel, or Persian cumin is a biennial plant in the family Apiaceae, native to western Asia, Europe and Northern Africa....
and others such as
ajwainTrachyspermum ammi, commonly known as ajowan, bishop's weed, ajwain, ajowan caraway, carom seeds, or thymol seeds, is a plant of India and the Near East whose seeds are used as a spice.-Characteristics:...
,
turmericTurmeric is a rhizomatous herbaceous perennial plant of the ginger family, Zingiberaceae. It is native to tropical South Asia and needs temperatures between 20 °C and 30 °C and a considerable amount of annual rainfall to thrive...
,
asafoetidaAsafoetida , alternative spelling asafetida, is the dried latex exuded from the living underground rhizome or tap root of several species of Ferula, which is a perennial herb...
(hing),
epazoteEpazote, wormseed, Jesuit's tea, Mexican tea, Paico or Herba Sancti Mariæ is an herb native to Central America, South America, and southern Mexico....
, and
kombuKombu or konbu , also called dashima or haidai , is edible kelp from the family Laminariaceae widely eaten in East Asia....
kelpKelps are large seaweeds belonging to the brown algae in the order Laminariales. There are about 30 different genera....
(a Japanese
seaweedSeaweed is a loose, colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...
). Most starches, including potatoes, corn, noodles, and wheat, produce gas as they are broken down in the large intestine. Rice is the only starch that does not cause gas. The amount of water-soluble
oligosaccharideAn oligosaccharide is a saccharide polymer containing a small number of component sugars, also known as simple sugars...
in beans that may contribute to production of intestinal gas is reputed to be reduced by a long period of soaking followed by boiling, but at a cost of also leaching out other water-soluble nutrients. Also, intestinal gas can be reduced by fermenting the beans, and making them less gas-inducing, and/or by cooking them in the liquor from a previous batch. Some
legumes also stand up to prolonged cooking, which can help break down the oligosaccharides into simple sugars. On the other hand, fermented bean products such as
misois a traditional Japanese seasoning produced by fermenting rice, barley and/or soybeans, with salt and the fungus , the most typical miso being made with soy. The result is a thick paste used for sauces and spreads, pickling vegetables or meats, and mixing with dashi soup stock to serve as miso...
are less likely to produce as much intestinal gas. Fermentative lactic acid bacteria such as
Lactobacillus caseiLactobacillus casei is a species of genus Lactobacillus found in the human intestine and mouth. As a lactic acid producer, it has been found to assist in the propagation of desirable bacteria. This particular species of Lactobacillus is documented to have a wide pH and temperature range, and...
and
Lactobacillus plantarumLactobacillus plantarum is a widespread member of the genus Lactobacillus, commonly found in many fermented food products as well as anaerobic plant matter. It is also present in saliva . It has the ability to liquefy gelatin. L...
reduce flatulence in human intestinal tract.
ProbioticProbiotics are live microorganisms thought to be beneficial to the host organism. According to the currently adopted definition by FAO/WHO, probiotics are: "Live microorganisms which when administered in adequate amounts confer a health benefit on the host"...
s (live yogurt,
kefirKefir is a fermented milk drink that originated with shepherds of the North Caucasus region, who discovered that fresh milk carried in leather pouches would occasionally ferment into an effervescent beverage...
, etc.) are reputed to reduce flatulence when used to restore balance to the normal intestinal flora. Live (bioactive) yogurt contains, among other lactic bacteria,
Lactobacillus acidophilusLactobacillus acidophilus is a species in the genus Lactobacillus. L. acidophilus is a homofermentative species, fermenting sugars into lactic acid, which grows readily at rather low pH values and has an optimum growth temperature of 37 °C . L...
which may be useful in reducing flatulence.
L. acidophilusLactobacillus acidophilus is a species in the genus Lactobacillus. L. acidophilus is a homofermentative species, fermenting sugars into lactic acid, which grows readily at rather low pH values and has an optimum growth temperature of 37 °C . L...
may make the intestinal environmnent more acidic, supporting a natural balance of the fermentative processes.
L. acidophilusLactobacillus acidophilus is a species in the genus Lactobacillus. L. acidophilus is a homofermentative species, fermenting sugars into lactic acid, which grows readily at rather low pH values and has an optimum growth temperature of 37 °C . L...
is available in supplements (some believe non-dairy is best). Prebiotics, which generally are non-digestible oligosaccharides, such as
fructooligosaccharideFructooligosaccharides also sometimes called oligofructose or oligofructan, are oligosaccharide fructans, used as an alternative sweetener. FOS exhibits sweetness levels between 30 and 50 percent of sugar in commercially-prepared syrups...
, generally increase flatulence in a similar way as described for lactose intolerance.
Medicinal
activated charcoalActivated carbon, also called activated charcoal, activated coal or carbo activatus, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.The word activated in the name is sometimes replaced...
tablets have also been reported as effective in reducing both odor and quantity of flatus when taken immediately before food that is likely to cause flatulence later.
Pharmacological
Digestive enzyme'Digestive enzymes' are enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body. Digestive enzymes are found in the digestive tract of animals where they aid in the digestion of food as well as inside the cells,...
supplements may significantly reduce the amount of flatulence caused by some components of foods not being digested by the body and thereby promoting the action of microbes in the small and large intestines. It has been suggested that
alpha-galactosidaseAlpha-galactosidase is a glycoside hydrolase enzyme that hydrolyses the terminal alpha-galactosyl moieties from glycolipids and glycoproteins. It is encoded by the gene.- Function :...
enzymes, which can digest certain complex sugars, are effective in reducing the volume and frequency of flatus. The enzymes
alpha-galactosidaseAlpha-galactosidase is a glycoside hydrolase enzyme that hydrolyses the terminal alpha-galactosyl moieties from glycolipids and glycoproteins. It is encoded by the gene.- Function :...
,
lactaseLactase , a part of the β-galactosidase family of enzymes, is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers...
,
amylaseAmylase is an enzyme that catalyses the breakdown of starch into sugars. Amylase is present in human saliva, where it begins the chemical process of digestion. Food that contains much starch but little sugar, such as rice and potato, taste slightly sweet as they are chewed because amylase turns...
,
lipaseA lipase is an enzyme that catalyzes the formation or cleavage of fats . Lipases are a subclass of the esterases.Lipases perform essential roles in the digestion, transport and processing of dietary lipids in most, if not all, living organisms...
,
proteaseA protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....
,
cellulase400px|thumb|right|alt = Colored dice with checkered background|Ribbon representation of the Streptomyces lividans beta-1,4-endoglucanase catalytic domain - an example from the family 12 glycoside hydrolases...
, glucoamylase,
invertaseInvertase is an enzyme that catalyzes the hydrolysis of sucrose . The resulting mixture of fructose and glucose is called inverted sugar syrup. Related to invertases are sucrases. Invertases and sucrases hydrolyze sucrose to give the same mixture of glucose and fructose...
, malt
diastaseA diastase is any one of a group of enzymes which catalyses the breakdown of starch into maltose. Alpha amylase degrades starch to a mixture of the disaccharide maltose, the trisaccharide maltotriose, which contains three α -linked glucose residues, and oligosaccharides known as dextrins that...
,
pectinasePectinase is a general term for enzymes, such as pectolyase, pectozyme and polygalacturonase, commonly referred to in brewing as pectic enzymes. These break down pectin, a polysaccharide substrate that is found in the cell walls of plants. One of the most studied and widely used commercial...
, and
bromelainBromelain is a pineapple extract thought to be effective for reducing swelling , especially of the nose and sinuses, after surgery or injury. It may also be used for a variety of other effects that remain scientifically unconfirmed and not authorized by regulatory authorities like the Food and Drug...
are available, either individually or in combination blends, in commercial products.
The
antibioticAn antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
rifaximin, often used to treat
diarrheaDiarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
caused by the
microorganismA microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
E. coli, may reduce both the production of intestinal gas and the frequency of flatus events.
While not affecting the production of the gases themselves, surfactants (agents which lower
surface tensionSurface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects to run on the water surface...
) can reduce the disagreeable sensations associated with flatulence, by aiding the dissolution of the gases into liquid and solid fecal matter.
Preparations containing
simethiconeSimethicone is an oral anti-foaming agent used to reduce bloating, discomfort and pain caused by excess gas in the stomach or intestinal tract. It is a mixture of polydimethylsiloxane and silica gel.-Chemical action and pharmaceutical effects:...
reportedly operate by promoting the coalescence of smaller bubbles into larger ones more easily passed from the body, either by burping or flatulence. Such preparations do not decrease the total amount of gas generated in or passed from the colon, but make the bubbles larger and thereby allowing them to be passed more easily.
OdorAn odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors...
from flatulence, caused by the intestinal bacteria called microflora in the bowel, can be treated by taking
bismuth subgallateBismuth subgallate, with a chemical formula C7H5BiO6, is the active ingredient in Devrom , an over-the-counter FDA-approved medicine commonly used to treat malodor by deodorizing flatulence and stool. Also, it has been used to treat Helicobacter pylori infection and is used in wound therapy...
, available over-the-counter as Devrom. Bismuth subgallate is commonly used by individuals who have had ostomy surgery,
bariatric surgeryBariatric surgery includes a variety of procedures performed on people who are obese. Weight loss is achieved by reducing the size of the stomach with an implanted medical device or through removal of a portion of the stomach or by resecting and re-routing the small intestines...
,
fecal incontinenceFecal incontinence is the loss of regular control of the bowels. Involuntary excretion and leaking are common occurrences for those affected. Subjects relating to defecation are often socially unacceptable, thus those affected may be beset by feelings of shame and humiliation...
and
irritable bowel syndromeIrritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
.
Post-release
In 1998, Chester "Buck" Weimer of
Pueblo, ColoradoPueblo is a Home Rule Municipality that is the county seat and the most populous city of Pueblo County, Colorado, United States. The population was 106,595 in 2010 census, making it the 246th most populous city in the United States....
received a patent for the first
undergarmentUndergarments or underwear are clothes worn under other clothes, often next to the skin. They keep outer garments from being soiled by bodily secretions and discharges, shape the body, and provide support for parts of it. In cold weather, long underwear is sometimes worn to provide additional...
that contained a replaceable
charcoal filterActivated carbon, also called activated charcoal, activated coal or carbo activatus, is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.The word activated in the name is sometimes replaced...
. The undergarments are
air-tightA hermetic seal is the quality of being airtight. In common usage, the term often implies being impervious to air or gas. When used technically, it is stated in conjunction with a specific test method and conditions of usage.-Etymology :...
and provide a pocketed
escape holeThe path of least resistance describes the physical or metaphorical pathway that provides the least resistance to forward motion by a given object or entity, among a set of alternative paths. The concept is often used to describe why an object or entity takes a given path.In physics, the path of...
in which a charcoal filter can be inserted. In 2001 Mr Weimer received the
Ig Nobel PrizeThe Ig Nobel Prizes are an American parody of the Nobel Prizes and are given each year in early October for ten unusual or trivial achievements in scientific research. The stated aim of the prizes is to "first make people laugh, and then make them think"...
for Biology for his invention.
A similar product was released in 2002, but rather than an entire undergarment, consumers are able to purchase an insert similar to a
pantilinerA pantiliner is an absorbent piece of material used for feminine hygiene. It is worn in the gusset of a woman's panties...
that contains activated charcoal. The inventors, Myra and Brian Conant of Mililani, Hawaii still claim on their website to have discovered the undergarment product in 2002 (eight years after Chester Weimer filed for a patent for his product), but state that their tests "concluded" that they should release an insert instead.
Health effects
As a normal body function, the action of flatulence is an important signal of bowel activity, and hence is often documented by nursing staff following surgical or other treatment of patients. However, symptoms of excessive flatulence
can indicate the presence of
irritable bowel syndromeIrritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
or some other organic
diseaseA disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
. In particular, the sudden occurrence of excessive flatulence together with the onset of new symptoms provide reason for seeking further medical examination.
Flatulence is not poisonous; it is a natural component of various intestinal contents. However, discomfort may develop from the build-up of gas pressure if an attempt is made to refrain from releasing them. In theory, pathological distension of the bowel, leading to
constipationConstipation refers to bowel movements that are infrequent or hard to pass. Constipation is a common cause of painful defecation...
, could result if a person holds in flatulence.
Not all flatus is released from the body via the anus. When the
partial pressureIn a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture....
of any gas component of the intestinal
lumenA lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
is higher than its partial pressure in the
bloodBlood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
, that component enters into the bloodstream of the intestinal wall by the process of
diffusionMolecular diffusion, often called simply diffusion, is the thermal motion of all particles at temperatures above absolute zero. The rate of this movement is a function of temperature, viscosity of the fluid and the size of the particles...
. As the blood passes through the lungs, this gas can diffuse back out of the blood and be exhaled. If a person holds in flatus during daytime, it will often be released during sleep involuntarily when the body is relaxed. Some flatus can become trapped within the feces during its compaction and will exit the body, still contained within the fecal matter, during the process of
defecationDefecation is the final act of digestion by which organisms eliminate solid, semisolid or liquid waste material from the digestive tract via the anus. Waves of muscular contraction known as peristalsis in the walls of the colon move fecal matter through the digestive tract towards the rectum...
.
Society and culture
In many
cultureCulture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
s, human flatulence in public is regarded as embarrassing but, depending on context, can also be considered humorous. People will often strain to hold in the passing of gas when in polite company, or position themselves to conceal the noise and scent. In other cultures, it may be no more embarrassing than
coughA cough is a sudden and often repetitively occurring reflex which helps to clear the large breathing passages from secretions, irritants, foreign particles and microbes...
ing. In one instance in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, however, two teenaged boys were kicked off of a
school busA school bus is a type of bus designed and manufactured for student transport: carrying children and teenagers to and from school and school events...
for farting.
While the act of passing flatus in said cultures is generally considered to be an unfortunate occurrence in public settings, flatulence may, in casual circumstances and especially among children, be used as either a humorous supplement to a joke ("
pull my fingerPull my finger is a joke or prank regarding flatulence in which a mark is asked to pull the finger of the illusionist , who simultaneously farts so as to suggest a causal relationship between the pulling of the finger and the subsequent expulsion of gas...
"), or as a comic activity in and of itself. The social acceptability of flatulence-based humor in entertainment and the mass media varies over the course of time and between cultures. The humorous insult "I fart in your general direction" from the comedy film
Monty Python and the Holy GrailMonty Python and the Holy Grail is a 1974 British comedy film written and performed by the comedy group Monty Python , and directed by Gilliam and Jones...
has been reprinted on several posters, t-shirts, and hats.
In January 2011, the
MalawiThe Republic of Malawi is a landlocked country in southeast Africa that was formerly known as Nyasaland. It is bordered by Zambia to the northwest, Tanzania to the northeast, and Mozambique on the east, south and west. The country is separated from Tanzania and Mozambique by Lake Malawi. Its size...
Minister of Justice,
George ChapondaDr. George T. Chaponda born , is a Malawian diplomat and politician. He is currently the Minister for Justice and Constitutional Affairs....
, said that
Air Fouling LegislationThe 2011 Malawian Air Fouling Legislation is a section of the Local Courts bill submitted to the parliament of Malawi in February 2011 that bans fouling the air. When the Minister of Justice claimed that the bill made farting in public illegal, the story made headlines around the world...
would make public farting illegal in his country. The media had a field day with punning headlines when they reported the story. Later, the minister withdrew his statement.
In 2008, a farting application for the
iPhoneThe iPhone is a line of Internet and multimedia-enabled smartphones marketed by Apple Inc. The first iPhone was unveiled by Steve Jobs, then CEO of Apple, on January 9, 2007, and released on June 29, 2007...
raked in nearly $10,000 in one day.
Environmental impact
Flatulence is often blamed as a significant source of
greenhouse gasA greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
es, owing to the erroneous belief that the methane released by
livestockLivestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
is in the flatus. While livestock account for around 20% of global
methaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
emissions, 90–95% of that is released by exhaling or
burping Belching involves the release of gas from the digestive tract through the mouth. It is usually accompanied with a typical sound and, at times, an odor...
. Only 1–2% of global methane emissions come from livestock flatus.
Since
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
produces large amounts of agricultural product it is in the unique position of having high methane emissions from livestock compared to other greenhouse gas sources. The New Zealand government is a signatory to the
Kyoto ProtocolThe Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...
and therefore attempts are being made to reduce greenhouse emissions. To achieve this an agricultural emissions research levy was proposed, which promptly became known as a "fart tax" or "flatulence tax". It encountered opposition from farmers, farming lobby groups and opposition politicians.
In
Fresno, CaliforniaFresno is a city in central California, United States, the county seat of Fresno County. As of the 2010 census, the city's population was 510,365, making it the fifth largest city in California, the largest inland city in California, and the 34th largest in the nation...
, a system to harvest methane by-product from dairy cattle and convert it to usable bio-gas is being used, in a partnership with Pacific Gas & Electric (PG&E) and BioEnergy Solutions, in which BioEnergy Solutions sells the methane harvested from cows to PG&E, who then converts the methane to usable bio-gas, which is very similar to natural gas.
Farting at will
Historical comment on the ability to fart at will is observed as early as
Saint AugustineAugustine of Hippo , also known as Augustine, St. Augustine, St. Austin, St. Augoustinos, Blessed Augustine, or St. Augustine the Blessed, was Bishop of Hippo Regius . He was a Latin-speaking philosopher and theologian who lived in the Roman Africa Province...
's
The City of God (5th century AD). Augustine mentions men who "have such command of their bowels, that they can break wind continuously at will, so as to produce the effect of singing". The fact that mankind in general has lost this ability he attributes to the first sin of
Adam and EveAdam and Eve were, according to the Genesis creation narratives, the first human couple to inhabit Earth, created by YHWH, the God of the ancient Hebrews...
and its consequences with respect to body control. Intentional passing of gas and its use as entertainment for others appear to have been somewhat well known in pre-modern Europe, according to mentions of it in medieval and later literature, including Rabelais.
Le PétomaneLe Pétomane was the stage name of the French flatulist and entertainer Joseph Pujol . He was famous for his remarkable control of the abdominal muscles, which enabled him to seem to fart at will. His stage name combines the French verb péter, "to fart" with the -mane, "-maniac" suffix, which...
("the Fartiste") was a famous French performer in the 19th century who, as well as many professional farters before him, did flatulence impressions and held shows. The performer
Mr. MethanePaul Oldfield, born in Macclesfield, Cheshire, North West England, is better known by his stage name Mr. Methane. He is a British flatulist or "professional farter" who started performing in 1991; he briefly retired in 2006 but re-started in mid-2007; he claims to be the only performing...
carries on le Pétomane's tradition today. Also, a 2002 film
ThunderpantsThunderpants is a 2002 family film about a boy whose incredible capacity for flatulence gets him a job as an astronaut. The film was directed by Pete Hewitt, whose previous work included Bill & Ted's Bogus Journey and The Borrowers...
revolves around a boy named Patrick Smash who has an ongoing flatulence problem since he was a newborn baby. He eventually overcame his problems and fulfilled his dreams including being an
astronautAn astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....
.
See also
- Tympanites
Tympanites , also known as meteorism, is a medical condition in which excess gas accumulates in the gastrointestinal tract.-Possible causes:* Bowel obstruction* Renal stones* Functional disorder* Overeating...
- Antiflatulent
An antiflatulent agent is a drug used for the alleviation or prevention of excessive intestinal gas, i.e., flatulence.- Preventing gas :* Enzymes - Enzyme-based dietary supplements break down indigestible substances and prevent these substances from reaching the large intestine intact -- where...
- Flatulence humor
Flatulence humor refers to any type of joke, practical joke device, or other humor related to flatulence.-History of flatulence humor:Although it is likely that flatulence humor has long been considered funny in cultures that consider the public passing of gas impolite, such jokes are rarely recorded...
- Borborygmus
Borborygmus also known as stomach growling, rumbling, gurgling, grumbling or wambling, is the rumbling sound produced by the contraction of muscles in the stomach and intestines of animals, including humans...
- Vaginal flatulence
Vaginal flatulence is an emission or expulsion of air from the vagina that may occur during or after sexual intercourse or during other sexual acts, stretching or exercise. The sound is somewhat comparable to flatulence from the anus but does not involve waste gases and thus often has no specific...
- The Gas We Pass
The Gas We Pass: The Story of Farts is a children's book written by Shinta Cho. The book tells children about flatulence , and that it is completely natural to do so....
- Fart lighting
Fart lightning or pyroflatulence is the practice of igniting the gases produced by human flatulence, often producing a flame of a blue hue, hence the act being known colloquially as a "blue angel", or in Australia, a "blue flame". The fact that flatus is flammable, and the actual combustion of it...
- Le Pétomane
Le Pétomane was the stage name of the French flatulist and entertainer Joseph Pujol . He was famous for his remarkable control of the abdominal muscles, which enabled him to seem to fart at will. His stage name combines the French verb péter, "to fart" with the -mane, "-maniac" suffix, which...
External links