Gas in the Digestive Tract On this page: - What is gas? - What
causes gas? - Which foods cause gas? - What are the symptoms of
gas? - How is the cause of gas found? - How is gas treated? -
Eating, Diet, and Nutrition - Points to Remember - Hope through
Research - For More Information What is gas? Gas is air in the
digestive tract—the 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. What causes gas? Gas
in the digestive t