High altitude flatus expulsion
Encyclopedia
High altitude flatus expulsion (HAFE) 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. 1820, it was rediscovered in 1981 by Paul Auerbach
and York Miller.
Informal review by peers of Auerbach and Miller noted earlier works of subtle title, such as that by Davis, as early as 1972.
The phenomenon is based on the differential in atmospheric pressure, directly correlated with the observer's frequency of and level of experience in high-altitude metabolism. As the external pressure decreases, the difference in pressure between the gas within the body and the atmosphere outside is higher, and the urge to expel gas to relieve the pressure is greater. Consistent with Boyle's law
, controlling for dietary variance, the amount of gas produced is constant in mass, but the volume increases as the external pressure decreases.
The feeling of fullness or need to expel brought on by this differential in atmospheric pressure has been verified by studies involving military pilots subjected to pressure changes simulating flight.
The condition is also known by backpackers as High Altitude Gas (HAG).
Paul Auerbach
Paul Stuart Auerbach is an American physician who is a leading voice in the area of wilderness medicine. He is a founder and past president of the Wilderness Medical Society. Auerbach was the editor for the Journal of Wilderness Medicine published by the Wilderness Medical Society from 1990 to 1995...
and York Miller.
Informal review by peers of Auerbach and Miller noted earlier works of subtle title, such as that by Davis, as early as 1972.
The phenomenon is based on the differential in atmospheric pressure, directly correlated with the observer's frequency of and level of experience in high-altitude metabolism. As the external pressure decreases, the difference in pressure between the gas within the body and the atmosphere outside is higher, and the urge to expel gas to relieve the pressure is greater. Consistent with Boyle's law
Boyle's law
Boyle's law is one of many gas laws and a special case of the ideal gas law. Boyle's law describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system...
, controlling for dietary variance, the amount of gas produced is constant in mass, but the volume increases as the external pressure decreases.
The feeling of fullness or need to expel brought on by this differential in atmospheric pressure has been verified by studies involving military pilots subjected to pressure changes simulating flight.
The condition is also known by backpackers as High Altitude Gas (HAG).