Gas (Flatulence), Bloating, & Belching

Intestinal Gas Causes
Which Foods Cause Gas and Flatulence?
What Are the Symptoms of Gas?
What Diagnostic Tests Are Used?
How Is Gas Treated?
Your Next Step

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Gas in the digestive tract (esophagus, stomach, small intestine, and large intestine) comes primarily from two sources:

Undigested foods. The body does not digest and absorb some carbohydrates (the sugar, starches, and fiber found in many foods) in the small intestine because of a shortage or absence of certain enzymes. This undigested food passes from the small intestine into the large intestine, where normal, bacteria break down the food, producing gases that exit through the rectum.

Foods that produce gas or flatulence in one person may not cause gas in another. Some common bacteria in the large intestine can destroy the hydrogen that other bacteria produce. The balance of the two types of bacteria may explain why some people have more flatulence than others.


Which Foods Cause Gas and Flatulence?

Some foods contain significant quantities of non-absorbable complex carbohydrates that pass into the colon, providing raw material for gas-producing bacteria.

Sugars. The food sugars that cause gas are raffinose, lactose, fructose, and sorbitol.

  • Raffinose. Beans contain large amounts of this complex sugar. Smaller amounts are found in cabbage, brussels sprouts, broccoli, asparagus, other vegetables, and whole grains.
  • Lactose. Lactose is the natural sugar in milk. It is also found in milk products, such as cheese and ice cream, and processed foods, such as bread, cereal, and salad dressing. Many people have a lactose intolerance and may experience increasing amounts of gas after eating food containing lactose. This problem can be solved by taking lactase powder with your meals.
  • Fructose. Fructose is naturally present in onions, artichokes, pears, and wheat. It is also used as a sweetener in some soft drinks and fruit drinks.
  • Sorbitol. Sorbitol is a sugar found naturally in fruits, including apples, pears, peaches, and prunes. It is also used as an artificial sweetener in many dietetic foods and sugar-free candies and gums.

Starches. Most starches, including potatoes, corn, noodles, and wheat, produce gas as they are broken down in the large intestine. Rice is the only starch that does not cause gas.

Fiber. Many foods contain soluble and insoluble fiber. Insoluble fiber passes through the intestines without causing gas. However, soluble fiber dissolves easily in water and takes on a soft, gel-like texture in the intestines. Found in oat bran, beans, peas, and most fruits, soluble fiber is not broken down until it reaches the large intestine, where its digestion causes gas.


What Are the Symptoms of Gas?

The most common symptoms of gas are flatulence, abdominal bloating, abdominal pain, and belching. However, the severity of your symptoms may depend on how much gas your body produces and your sensitivity to gas in the large intestine.

Belching. An occasional belch during or after meals is normal and releases gas when the stomach is full of food.

A person with chronic belching may have an upper GI disorder, such as peptic ulcer disease, gastroesophageal reflux disease (GERD), or gastroparesis. Another possible contributor to belching is a lack of stomach acid needed to break down foods.

Flatulence. Another common complaint is passage of too much gas through the rectum (flatulence). However, most people do not realize that a little bit of flatulence is normal. Too much flatulence may be the result of carbohydrate malabsorption or food allergies.

Abdominal bloating. Many believe that too much gas causes abdominal bloating. However, people who complain of bloating from gas often have normal amounts and distribution of gas. They are just very sensitive to gas in the digestive tract.

However, doctors believe that bloating is usually the result of an intestinal disorder:

  • Irritable bowel syndrome (IBS). IBS may involve abnormal movements and contractions of intestinal muscles and increased pain sensitivity in the intestine that is often caused by food allergies. Intestinal disorders may give a sensation of bloating because of increased sensitivity to gas.
  • Any chronic disease that causes intestinal inflammation or obstruction, such as Crohn's disease or colon cancer, may also cause abdominal bloating.
  • A parasitic infection in the intestines may cause bloating.
  • People who have had many operations, adhesions (scar tissue), or internal hernias may experience bloating or pain.
  • Eating a lot of fatty food can delay stomach emptying and cause bloating and discomfort, but not necessarily too much gas.

Abdominal pain and discomfort. Some people have pain when gas is present in the intestine. When pain is on the left side of the colon, it can be confused with heart disease. When the pain is on the right side of the colon, it may mimic gallstones or appendicitis.


What Diagnostic Tests Are Used?

Excessive gas, flatulence, bloating and belching often indicate a food allergy or intolerance. Therefore, you should have a comprehensive Food Allergy Panel performed.

  • If milk products appear to be involved, we may order lab tests to determine whether you have a milk allergy or lactose intolerance, or both.

  • You may have a bacterial, fungal, or parasitic infection in your gut. Depending on your medical history and symptoms, the doctor may order lab tests to find out if you are infected.

  • Another cause of gas and bloating is the inability to digest food. There is a lab test available that will tell you whether or not the food you eat is being properly digested.

Treatment for Intestinal Gas

Experience has shown that the most effective ways to reduce the discomfort of gas are through the avoidance of food allergies and food intolerances.

Diet Modification. We may also suggest limiting high-fat foods to reduce bloating and discomfort. This helps the stomach empty faster, allowing gases to move into the small intestine.

However, the amount of gas caused by certain foods varies from person to person. Effective dietary changes depend on learning through testing and through trial and error how much of the offending foods you can handle.

Natural Treatments Bloating - Natural Treatments Flatulence. There are a number of digestive aids that can relieve symptoms if your problem is due to deficiency in digestive enzymes.

  • Activated charcoal tablets (Charcocaps) may provide relief from gas in the colon. Studies have shown that when these tablets are taken before and after a meal, intestinal gas and flatulence is reduced. The usual dose is 2 to 4 tablets taken just before eating and 1 hour after meals.

  • The enzyme lactase, which aids with lactose digestion, is available in liquid and tablet form without a prescription (Lactaid, Lactrase, and Dairy Ease). Adding a scoop of Lactase Powder to milk before drinking it or just before eating helps digest foods that contain lactose. Also, lactose-reduced milk and other products are available at many grocery stores (Lactaid and Dairy Ease).

  • Beano, an over-the-counter digestive aid, contains the sugar-digesting enzyme that the body lacks to digest the sugar in beans and many vegetables. The enzyme comes in liquid form. Three to 10 drops are added per serving just before eating to break down the gas-producing sugars. Beano has no effect on flatulence caused by lactose or fiber.

  • If you have a compromised ability to digest foods, we may prescribe pancreatic or plant-based enzymes to help you digest food.

Avoid over-the-counter antacids. While they may provide temporary symptomatic relief, they do not solve the problem of indigestion. Studies have suggested that some antacids are actually unhealthy.

Treatment of Chronic Disease or Infection. If you have an underlying disorder that is causing gas, bloating and belching, we will prescribe the appropriate therapy.


Your Next Step

If you feel that you have a problem with gas, flatulence, bloating or belching -- and you are looking for a permanent solution rather than depending on symptomatic relief with antacids -- call 206-264-1111 today. You may have an underlying identifiable disorder that is causing these symptoms.

Dr. Stephen Wangen
IBS Treatment Center and Center for Food Allergies
11300 Roosevelt Way NE Suite 100 Seattle, WA 98125 · 206-264-1111

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