Definition & Facts for Gas in the Digestive Tract

What is gas?

Gas is air in your digestive tract. Gas leaves your body through your mouth when you burp or through your anus when you pass gas.

Flatulence is excess gas in your stomach or intestines that can cause bloating and flatus. Flatus, gas that leaves your body through your anus, can contain small amounts of sulfur. Flatus that contains more sulfur has more of an odor.

Learn more about your digestive tract and how it works.

How common is gas?

Everyone has gas. People may think that they burp or pass gas too often and that they have too much gas. Having too much gas is uncommon.

Who is more likely to get gas?

Certain conditions may cause you to have more gas or to have more symptoms when you have a normal amount of gas in your digestive tract. People who swallow more air or eat certain foods may be more likely to have more gas.

Last Reviewed July 2016

This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.