Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at December 10, 2015

In most instances, flatulence is a perfectly normal biological function. Everyone passes gas on a daily basis. Unfortunately, gas can be physically uncomfortable and can be awkward and embarrassing in social situations when accompanied by an audible release of wind and an unmistakable odor. The following examines common causes of gas, how it can be prevented, and when it can be a sign of an underlying health condition requiring the attention of a medical professional.


Definition & Facts

Flatulence is the byproduct of the digestive process. As food is processed by the digestive system, it produces gas comprised mainly of methane, hydrogen, oxygen, and nitrogen. The methane and hydrogen make the flatus flammable while trace amounts of indole, skatole, and sulfur compounds provide the unpleasant odor. The body releases as much as one to four pints of excess gas a day through the mouth in the form of belching or through the anus as flatulence.

The average person releases excess gas as often as 20 times per day. In most cases, the person is unaware of the flatulence since there is no sound, and very little wind is expelled. When excess gas builds up in the body, it can cause symptoms such as bloating and abdominal pain. In some cases, the abdominal pain may be so severe that it mimics the symptoms of a heart attack or appendicitis.


Gas is formed within the body either by swallowing air during eating and drinking or when intestinal bacteria start to digest food. Although people have different sensitivities, certain foods are more likely to cause gas and flatulence than others. Some common gas-producing foods include:

  • Foods high in carbohydrates, such as beans.
  • Cruciferous vegetables, such as cabbage, broccoli, and onions.
  • Fruits and fruit juices.
  • Soft drinks, especially those containing sorbitol.
  • Dairy products.
  • Whole grain foods.
  • Swallowing air by eating or drinking too quickly, sucking on hard candy, smoking, chewing gum, or wearing loose dentures.
  • Certain prescription medications, such as cholesterol-lowering statins.

When to see a doctor

Even though gas is usually a minor annoyance, the following symptoms should not be ignored:

  • Flatulence that occurs frequently or involuntarily.
  • Extremely foul smelling flatus.
  • Gas accompanied by sharp, abdominal cramps that may seem to change location in the abdomen.
  • A knot-like sensation in the abdomen.
  • Flatulence accompanied by the release of a lot of wind.

Chronic belching or flatulence can be a symptom of a disorder involving the upper or lower gastrointestinal tract. Persistent belching may be a sign of gastroesophageal reflux disease, also known as GERD, or even an stomach ulcer. Bloating can be an indicator of a number of conditions, including Crohn’s disease, irritable bowel syndrome, hernias, or even colon cancer. A doctor will try to identify the cause of the chronic flatulence by using a combination of the following methods:

  • A food elimination diet to rule out potential food sensitivities. This process starts with the patient keeping a detailed record of the foods consumed and the frequency and severity of flatulence symptoms. Suspected gas-producing foods are then eliminated one-by-one to see if symptoms improve.
  • Breath tests to assess for an increase in hydrogen indicating a possible food intolerance.
  • Physical examination to assess for inflammation or fluid build-up in the abdomen that may indicate problems with the colon or liver.
  • Colorectal screenings to rule out colon cancer. This is especially important if the chronic gas is accompanied by diarrhea, bloody stool, or unexplained weight loss.
  • X-rays of the upper gastrointestinal tract to rule out problems with the stomach, esophagus, and the upper portion of the small intestine.
  • Analysis of the gas content of the flatus to determine if it is from swallowed air or the gastrointestinal tract.

Treatment & Therapy

Treatment for flatulence depends on the exact cause. Common treatments involve dietary changes and both over-the-counter and prescription medications.

  • Dietary changes and food elimination should be supervised by a physician or dietician. Many of the foods that can cause gas are also quite healthy. It is important to construct a diet that still provides essential vitamins and nutrients.
  • Probiotics can reduce the number of bad bacteria and increase the number of good bacteria in the GI tract, which can aid the digestive process.
  • Antacids containing the anti-foaming agent simethicone can relieve bloating caused by excess gas.
  • Digestive enzymes, such as Beano®, help digest sugars in beans and other vegetables.
  • Over-the-counter lactase products can help prevent excess gas related to dairy intolerance.
  • Activated charcoal tablets taken before and after meals may provide some relief from excess gas.
  • Prescription medications are often required if the flatulence is related to digestive disorders such as irritable bowel syndrome. For example, metoclopramide helps speed up the movement of food through the gastrointestinal tract. This means that undigested food has less opportunity to ferment and create gas in the colon.
  • Surgery may be required if the flatulence is due to a condition such as colon cancer or Hiatus hernia.

Prevention & Prophylaxis

The best way to reduce or prevent embarrassing flatulence involves simple lifestyle modifications.

  • Attempt to identify and avoid offending foods.
  • Choose easy-to-digest carbs, such as rice, bananas, lettuce, citrus fruits, and grapes.
  • Avoid carbonated beverages.
  • Eat slowly, and take the time to chew foods thoroughly to avoid swallowing excess air.
  • Make sure dentures fit properly.
  • Don’t eat hard candies or chew gum.
  • Avoid overeating since it slows down the digestive process
  • Eat six small meals a day instead of three large meals to avoid overwhelming the gastrointestinal tract.
  • Drink liquids before meals to help your stomach digest better.
  • Avoid activities, such as smoking or using straws, which involve sucking in air.
  • Use over-the-counter antacids or gas medications when eating foods that may cause flatulence.
  • Reduce the odor of flatulence by using charcoal liners in underwear to absorb released gas.

Treating flatulence often involves trial and error. In most cases, a significant reduction in gas symptoms is achieved through a combination of dietary changes and over-the-counter remedies. Individuals with flatulence related to a medical condition may require further treatments depending on the underlying cause. A physician should be consulted if gas is persistent or causes severe physical or emotional distress.

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