Gas is a normal byproduct of the foods we eat. As the digestive
system breaks food down, it produces gas, which is mainly
composed of carbon dioxide, oxygen, nitrogen, hydrogen, and
methane. Usually, we eliminate gas through the mouth (burping)
or through the anus (flatulance). We typically pass gas around
20 times a day. Gas is an ordinary occurrence, but its presence
can be painful and socially embarrassing. We produce gas in two
ways: when we swallow air, and when the bacteria in the large
intestine go to work helping to digest the food we eat.
Carbohydrates are especially troublesome. Humans cannot digest
certain carbohydrates in the small intestine because we may not
have (or not have enough of) the enzymes that can aid in their
digestion. This food moves in the undigested state from the
small intestine to the large intestine; it is here that the
bacteria go to work, producing the gases hydrogen, carbon
dioxide, and methane which are then expelled from the body. Not
everybody will suffer from gas from ea