What is (are) Gas in the Digestive Tract ?
Gas is air in the digestive tractthe large, muscular tube that extends from the mouth to the anus, where the movement of muscles, along with the release of hormones and enzymes, allows for the digestion of food. Gas leaves the body when people burp through the mouth or pass gas through the anus.
                
Gas is primarily composed of carbon dioxide, oxygen, nitrogen, hydrogen, and sometimes methane. Flatus, gas passed through the anus, may also contain small amounts of gasses that contain sulfur. Flatus that contains more sulfur gasses has more odor.
                
Everyone has gas. However, many people think they burp or pass gas too often and that they have too much gas. Having too much gas is rare.