Farts - also called flatus (say: flay-tus) or intestinal (say: in-tes-tuh-null) gas - are made of, well, gas!
When you eat, you don't swallow just your food. You also swallow air, which contains gases like nitrogen (say: ny-truh-jen) and oxygen (say: ahk-sih-jen). Small amounts of these gases travel through your digestive system as you digest your food. Other gases like hydrogen (say: hy-droh-jen), carbon dioxide (say: kar-bon dy-ahk-side, the gas that makes soda fizzy), and methane (say: meth-ain) are made when food is broken down in the large intestine. All of these gases in the digestive system have to escape somehow, so they come out as farts.
AGAIN
