CausesBy Mayo Clinic staff
Excess upper intestinal gas may result from swallowing more than a usual amount of air while eating, drinking or chewing gum. Lower intestinal gas is the normal byproduct of bacterial action on food that is not broken down until reaching the colon. Intestinal gas related to bacterial action is made up of hydrogen, carbon dioxide and sometimes methane.
Foods that cause gas
Some foods contain substances that aren't fully digested until they are acted upon (metabolized) by the bacteria in the lower intestine, where they're broken down into simpler substances, including gas. Common gas-producing foods and substances include:
- Beans and lentils
- Dairy products containing lactose
- Fructose and sorbitol, which are found in some fruits and are also used as sweeteners
Digestive disorders that cause gas
Excessive intestinal gas — belching or flatulence more than 20 times a day — sometimes indicates a digestive disorder such as:
Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.
- Gas in the digestive tract. National Institute of Diabetes and Digestive and Kidney Diseases. http://digestive.niddk.nih.gov/ddiseases/pubs/gas/. Accessed April 10, 2013.
- Belching, bloating and flatulence. The American College of Gastroenterology. http://patients.gi.org/topics/belching-bloating-and-flatulence/. Accessed April 10, 2013.
- Feldman M, et al. Sleisenger & Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 9th ed. Philadelphia, Pa.: Saunders Elsevier; 2010. http://www.mdconsult.com/books/about.do?eid=4-u1.0-B978-1-4160-6189-2..X0001-7--TOP&isbn=978-1-4160-6189-2&about=true&uniqId=229935664-2192. Accessed March 30, 2013.
- Gas-related complaints. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/gastrointestinal_disorders/approach_to_the_patient_with_lower_gi_complaints/gas-related_complaints.html. Accessed April 10, 2013.
- Wilkinson JM (expert opinion). Mayo Clinic, Rochester, Minn. April 12, 2013.