Functional constipation

Functional constipation is constipation

Constipation

Constipation, costiveness, or irregularity is a condition of the digestive system in which a person experiences hard feces that are difficult to expel. This usually happens because the colon absorbs too much water from the food...

 that does not have a physical (anatomical) or physiological

Physiology

Physiology is the science of the functioning of living systems. It is a subcategory of biology...

 (hormonal or other body chemistry) cause. It may have a neurological

Neurology

Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...

, psychological

Psychology

Psychology is an academic and applied discipline involving the systematic, and sometimes scientific, study of human or animal mental functions and behavior...

 or psychosomatic cause. A person with functional constipation may be healthy, yet has difficulty defecating

Defecation

Defecation is the final act of digestion by which organisms eliminate solid, semisolid or liquid waste material from the digestive tract via the anus. Humans usually defecate from three times a week, up to three times a day...

.

Functional constipation is constipation

Constipation

Constipation, costiveness, or irregularity is a condition of the digestive system in which a person experiences hard feces that are difficult to expel. This usually happens because the colon absorbs too much water from the food...

 that does not have a physical (anatomical) or physiological

Physiology

Physiology is the science of the functioning of living systems. It is a subcategory of biology...

 (hormonal or other body chemistry) cause. It may have a neurological

Neurology

Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...

, psychological

Psychology

Psychology is an academic and applied discipline involving the systematic, and sometimes scientific, study of human or animal mental functions and behavior...

 or psychosomatic cause. A person with functional constipation may be healthy, yet has difficulty defecating

Defecation

Defecation is the final act of digestion by which organisms eliminate solid, semisolid or liquid waste material from the digestive tract via the anus. Humans usually defecate from three times a week, up to three times a day...

.

Functional constipation, as medically defined by the Rome III criteria, has many causes, including:

• Anismus
  Anismus
  Anismus is a malfunction of the external anal sphincter and puborectalis muscle during defecation. Normal defecation involves relaxation of both of these muscles...
  
  
• Descending perineum syndrome
• Hirschsprung's disease
  Hirschsprung's disease
  Hirschsprung's disease, or congenital aganglionic megacolon, involves an enlargement of the colon, caused by bowel obstruction resulting from an aganglionic section of bowel that starts at the anus and progresses upwards...
  
  
• Other inability or unwillingness to control the external anal sphincter, which normally is under voluntary
  Volition
  Volition can mean:*Volition *Volition *Volition, Inc., a video game developer*Volition Records, a record label...
  
   control
• A bad diet
  Diet (nutrition)
  In nutrition, the diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. Although humans are omnivores, each culture holds some food preferences and some food taboos. Individual...
  
  
• an unwillingness to defecate
• nervous reactions, including prolonged and/or chronic stress and anxiety, that close the internal anal sphincter
  Sphincter ani internus muscle
  The Sphincter ani internus is a muscular ring which surrounds about 2.5 cm of the anal canal; its inferior border is in contact with, but quite separate from, the Sphincter ani externus....
  
  , a muscle
  Muscle
  Muscle is the contractile tissue of the body 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...
  
   that is not under voluntary control
• deeper psychosomatic disorders which sometimes affect digestion
  Digestion
  Digestion is the mechanical and chemical breaking down of food into smaller components, to a form that can be absorbed, for instance, by a blood stream. Digestion is a form of catabolism.that means break down of macro food molecules to smaller one....
  
   and the absorption of water
  Water
  Water is an ubiquitous chemical substance that is composed of hydrogen and oxygen and is essential for all known forms of life.In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71%...
  
   in the colon
  Colon (anatomy)
  The colon is the last portion of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body....