For the 2012 comedy film, see Breaking Wind. Flatus is also the medical word the gas we pass pdf gas generated in the stomach or bowels.
Despite these standard definitions, a proportion of intestinal gas may be swallowed environmental air, and hence flatus is not totally generated in the stomach or bowels. The scientific study of this area of medicine is termed flatology. It is normal for humans to pass flatus through the rectum, although the volume and frequency may vary greatly between individuals.
It is also normal for intestinal gas passed through the rectum to have a characteristic feculent smell, although this too may vary in concentration. Flatus is brought to the rectum by specialised contractions of the muscles in the intestines and colon. Both the noise and smell associated with flatus leaving the anus can be sources of embarrassment or comedy in many cultures.
There are five general symptoms related to intestinal gas: pain, bloating and abdominal distension, excessive flatus volume, excessive flatus smell and gas incontinence. Non-medical definitions of the term include “the uncomfortable condition of having gas in the stomach and bowels”, or “a state of excessive gas in the alimentary canal”. Derived terms include vaginal flatulence, otherwise known as a queef. Generally speaking, there are four different types of complaints that relate to intestinal gas, which may present individually or in combination.
Patients may complain of bloating as abdominal distension, discomfort and pain from “trapped wind”. However, three significant pieces of evidence refute this theory. The proportion of hydrogen produced may be increased in a subset of IBS patients, but this does not affect the total volume. Thirdly, it is known that the total volume of flatus produced by IBS patients who complain of pain and abdominal distension would be tolerated in normal subjects without any complaints of pain.