High altitude flatus expulsion

HAFE or high altitude flatus expulsion is a gastrointestinal syndrome which involves the spontaneous passage of increased quantities of rectal gases at high altitudes. [Medicine For the Outdoors by Paul S. Auerbach, M.D. © 1999 by Paul S. Auerbach, M.D.] First described by Joseph Hamel in c. 1820, [ [http://www.liebertonline.com/doi/abs/10.1089/152702901753397135?cookieSet=1&journalCode=ham Mary Ann Liebert, Inc. - High Altitude Medicine & Biology - 2(4):551 ] ] it was rediscovered in 1981 by Paul Auerbach and York Miller. [ [http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1272559 High Altitude Flatus Expulsion (HAFE) ] ]

Informal review by peers of Auerbach and Miller noted earlier work of subtle title, such as that by Davis, as early as 1972. [E.Y. Davis, FRCP(Ret), "Hafe In Nepal" West J Med. 1981 April; 134(4): 366, identifying "Flatulence Accompanying Rigorous Trekking," Kathmandu Medical Bulletin, 1972.]

The phenomenon is based on the differential in atmospheric pressure, directly correlated to the observer's frequency of and level of experience in high-altitude metabolism. As the external pressure decreases, the pressure within the body is relatively higher, and the urge to expel gas to relieve the pressure is relatively greater.

The subjective physiological 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. [ http://jap.physiology.org/cgi/pdf_extract/26/2/177 Greenwald, Allen, Bancroft, "Abdominal Gas Volume At Altitude And At Ground Level" J Appl Physiol 26: 177-181, 1969]

Also known by backpackers as High Altitude Gas (HAG).

ee also

*High altitude pulmonary edema (HAPE)
*High altitude cerebral edema (HACE)

References