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 (flatulence). 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 eating the same foods. We also swallow a certain amount of air when we eat and drink. This contributes to the production of gas. We usually release swallowed air by burping it out. Whatever isn’t released by burping goes into the small or large intestine, where it is eventually released as flatulence.