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Belching or passing gas (flatus) is natural and common. We all have gas in our intestinal tract. Gas can cause a sense of bloating (fullness), belching, abdominal cramps, and flatulence (gas). These symptoms are usually brief and resolve once gas is released by belching or flatulence. Some people can be more sensitive to even normal amounts of gas and develop symptoms.

The amount of gas produced by the body depends upon our diet and other individual factors. Certain foods and medical conditions can cause excessive amounts of gas.


  • Belching
  • Bloating
  • Flatulence
  • Abdominal pain, discomfort, and tightness


  • Excessive air swallowing. Most of us swallow air during eating. Some individuals who experience anxiety may swallow excessive amount of air. Chronic postnasal drip can also cause excess air swallowing.
  • Drinking carbonated beverages and certain foods can also generate excess gastric air. Some carbohydrates cannot be digested in the small intestine and reach the colon where bacteria metabolize them to produce gasses. Examples of such food are bran, cabbage, cauliflower, broccoli, and beans.
  • Lactose intolerance. Many patients experience abdominal cramps, bloating and flatulence when they ingest milk, certain cheeses or ice cream because they lack the enzyme (lactase) which is required to digest milk sugars (lactose).
  • Bacterial overgrowth. Another cause of bloating and abdominal distension is from bacterial overgrowth. This is not an infection but can happen when there is an excess amount of normal bacteria in the small intestine.
  • Constipation may also contribute to bloating and a sense of abdominal distention.


Some patients with Irritable Bowel Syndrome (IBS) appear to be uniquely sensitive to normal or only slightly increased volumes of intestinal gas and may develop abdominal cramps as a result. Patients with altered anatomy due to surgery may be at an increased risk of bacterial overgrowth in the small intestine which can lead to belching, bloating or flatulence.


The diagnosis of other gastroenterological problems should be excluded. Abdominal distension when erect but not when recumbent is an indication of weak abdominal muscles. If lactose intolerance is suspected, milk can be withdrawn from the diet and symptoms observed. However, lactose can be administered orally and the hydrogen gas which is generated in susceptible people can be measured in the breath. Postnasal discharge from sinus problems can cause air swallowing and should be considered. If bacterial overgrowth is suspected, your physician may administer a hydrogen breath test.

Blood tests are not usually helpful for gaseous problems but testing for celiac disease may prove useful since failure to absorb wheat, barley, and rye can lead to excess flatulence.


  • Diet modification. Foods such as cauliflower, broccoli, cabbage, beans, and bran should be avoided. Carbonated beverages need to be eliminated. Milk and other dairy foods should be avoided. Sugar-free gum and hard candies should be avoided.
  • Over the counter medications:
    • Simethicone products may be helpful in some people.
    • Charcoal tablets have also been used
    • Bismuth subsalicylate has been used to reduce the noxious odor of some sulfa-containing rectal gasses.
    • Alpha-d-galactosidase, an over the counter product, has been used to help in the digestion of complex carbohydrates.
  • Individuals with IBS may benefit from symptomatic therapy for “gas pains” by using antispasmodic therapy such as dicyclomine or hyoscyamine under the tongue.
  • Some patients with bacterial overgrowth may see improvement from the occasional use of antibiotics to reduce the number of bacteria in the small bowel, thereby reducing gas production.
  • If weak abdominal muscles are suspected as a cause for abdominal distension, abdominal-tensing exercises may be helpful, although very difficult to achieve when patients are middle aged and older.
  • If symptoms fail to respond to the dietary strategies noted above, medical help should be sought to be confident that no other underlying abnormalities are present.


  • Belching and flatulence are normal body processes.
  • Swallowed air is “gas” in the body and contributes significantly to symptoms.
  • Unabsorbed dietary carbohydrates can cause gas production by colon bacteria.
  • Carbonated beverages, sucking on hard candy, and chewing gum should be avoided.
  • Abdominal distension when erect but not recumbent may be due to weak abdominal muscles.
  • Increasing frequency or severity of symptoms should prompt medical attention.