1. Home
  2. Health Information
  3. Digestive Diseases
  4. Gas in the Digestive Tract

Gas in the Digestive Tract

View or Print All Sections

Definition & Facts

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. People may think that they burp or pass gas too often and that they have too much gas. However, having too much gas is rare.
man suffers from stomachache

Symptoms & Causes

The most common symptoms of gas include burping, passing gas, bloating, and pain in your abdomen. Gas normally enters your digestive tract when you swallow air and when bacteria in your large intestine break down certain undigested foods.


Doctors may diagnose the causes of gas with a medical history and physical exam. If your doctor suspects you may have a health condition, he or she may order more tests. Your doctor may ask you to keep a diary of your diet and gas symptoms.


To reduce or prevent gas and gas symptoms, your doctor may suggest that you reduce swallowed air, quit smoking, make changes to your diet, or take medicines. Some over-the-counter medicines may reduce gas. In some cases, doctors prescribe medicines.

Eating, Diet, & Nutrition

You may be able to reduce gas by avoiding or eating less of the foods that give you gas. You can use a food diary to help figure out which foods give you gas and how much of the foods you can handle. Talk with your doctor about changing your diet.

Clinical Trials

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.

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.