What causes flatulence?

Flatulence and belching are natural occurrences that result from eating or drinking too quickly. Eating certain foods or drinking carbonated beverages can also introduce air into the stomach and cause flatulence. Because infants frequently swallow air when feeding, they may have flatulence after they have been fed. The act of burping an infant helps relieve the discomfort caused by swallowed air.

Flatulence is also caused by the passage of undigested food from the small intestine to the large intestine. Bacteria in the large intestine process the food and produce harmless gases, such as carbon dioxide, hydrogen, and methane, which are released as gas through the rectum. Certain foods, such as carbohydrates, fiber and sugars, are more likely than other foods to cause gas.

Food causes of flatulence

Flatulence may be caused by eating certain foods including:

  • Fiber, especially soluble forms of fiber, which passes undigested until it reaches the large intestine
  • Starchy foods, such as breads and rice
  • Sugars, including fructose (found in some foods and sweeteners), lactose (found in dairy products), raffinose (found in brussels sprouts, broccoli, cabbage, and beans), and sorbitol (found in fruits and artificial sweeteners)

Gastrointestinal causes of flatulence

  • Almost any condition affecting the digestive tract can cause flatulence. These include conditions in which the normal movement or flow in the digestive tract is obstructed, interrupted or delayed. Examples include gastroparesis (delayed stomach emptying), intestinal obstruction, hiatal hernia, and gastrointestinal reflux disease (also known as GERD). In other types of disorders, the enzymes or processes that are needed to digest food completely are either deficient or absent. Examples include food intolerance and gallbladder disease.

Flatulence can be caused by many conditions affecting the digestive tract including:

  • Bowel obstruction
  • Food allergies (allergic reactions to certain foods) or food intolerances (difficulty digesting certain foods without symptoms of a food allergy)
  • Gallbladder disease
  • Gastritis (inflammation of the stomach lining)
  • Gastrointestinal reflux disease (GERD)
  • Gastroparesis (delayed stomach emptying)
  • Hiatal hernia
  • Malabsorption
  • Pancreatic disease
  • Peptic ulcer disease
  • Pregnancy
  • Tumors of the gastrointestinal tract

Serious or life-threatening causes of flatulence

Flatulence is a normal body process that is rarely serious in nature. However, in rare cases, flatulence may be a symptom of a serious or life-threatening condition that should be evaluated immediately in an emergency setting. These include:

  • Abdominal abscess
  • Obstruction of the digestive tract

Questions for diagnosing the cause of flatulence

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your flatulence including:

  • How long have you experienced flatulence?
  • Does your flatulence worsen when you consume certain foods or drinks?
  • Are you experiencing any other symptoms along with your flatulence?
  • Is your flatulence becoming worse or more frequent?

What are the potential complications of flatulence?

Flatulence is generally a harmless symptom that does not produce long-term complications. However, some of the gastrointestinal conditions associated with flatulence may have serious complications as a result of the underlying disease rather than the symptom of flatulence itself. For example, intestinal obstruction due to cancer is a condition that can have long-term and potentially serious or life-threatening complications.


  1. Gas in the digestive tract. National Digestive Diseases Information Clearinghouse (NDDIC). http://digestive.niddk.nih.gov/ddiseases/pubs/gas/index.htm.
  2. Gas - flatulence. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003124.htm.

What is flatulence?

Flatulence is the expulsion of gas from the gastrointestinal tract through the rectum. Daily, the average person produces one to four pints of gas and expels it up to 14 times. Although flatulence can cause embarrassment to some people, it is a natural occurrence (Source: Read more about flatulenceintroduction


What other symptoms might occur with flatulence?

Flatulence may be accompanied by other symptoms, depending on the underlying disease, disorder or condition. Symptoms that frequently affect the digestive tract may also involve other body systems.

Digestive symptoms that may occur along with flatulence

Flatulence may accompany other symptoms affecting the digestive tract including:

Medical Reviewer: All content has been reviewed by board-certified physicians under the direction of Rich Klasco, M.D., FACEP. Last Annual Review Date: May 2, 2011 Copyright: © Copyright 2011 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Digestive System

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