Flatulence is the expulsion through the rectum of
a mixture of gases that are byproducts of the digestion
process of mammals and other animals. The mixture
of gases is known as flatus in medical speak, informally
as a fart, or simply (in American English) gas,
and is expelled from the rectum in a process colloquially
referred to as "passing gas", "breaking
wind" or "farting"...