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Definition

Intestinal gas is a buildup of air in the digestive tract. It is usually not noticed until you burp or pass it rectally, called flatulence. The entire digestive tract, from the stomach to the rectum, contains intestinal gas. It is the natural result of swallowing and digestion.

In fact, certain foods, such as beans, are not fully broken down until they reach the colon in the large intestine. In the colon, bacteria act on these foods, which causes the gas.

Everyone passes gas several times daily. Occasional burping or flatulence is normal. However, too much intestinal gas sometimes indicates a digestive disorder.

Causes

Too much upper intestinal gas can come from swallowing more than a usual amount of air. It also can come from overeating, smoking, chewing gum or having loose-fitting dentures. Too much lower intestinal gas can be caused by eating too much of certain foods or not being able to fully digest certain foods. It also can be from a change in the bacteria found in the colon.

Foods that cause too much gas

Foods that cause gas in one person might not cause it in another. Common foods and substances that produce gas include:

• Beans and lentils
• Vegetables such as cabbage, broccoli, cauliflower, bok choy and Brussels sprouts
• Bran
• Dairy products containing lactose
• Fructose, which is found in some fruits and used as a sweetener in soft drinks and other products
• Sorbitol, a sugar substitute found in some sugar-free candies, gums and artificial sweeteners
• Carbonated beverages, such as soda or beer

Digestive disorders that cause too much gas

Too much intestinal gas means burping or flatulence more than 20 times a day. Sometimes it indicates a disorder such as:

• Celiac disease
• Colon cancer — cancer that starts in the part of the large intestine called the colon.
• Constipation — which can be chronic and last for weeks or longer.
• Eating disorders
• Functional dyspepsia
• Gastroesophageal reflux disease (GERD)
• Gastroparesis (a condition in which the muscles of the stomach wall don't function properly, interfering with digestion)
• Intestinal obstruction — when something blocks food or liquid from moving through the small or large intestine.
• Irritable bowel syndrome — a group of symptoms that affect the stomach and intestines.
• Lactose intolerance
• Ovarian cancer — cancer that starts in the ovaries.
• Pancreatic insufficiency

When to see a doctor

By itself, intestinal gas rarely means there is a serious condition. It can cause discomfort and embarrassment, but it's usually just a sign of a properly functioning digestive system. If you're bothered by intestinal gas, try changing your diet.

However, see your health care provider if your gas is severe or doesn't go away. Also see your provider if you have vomiting, diarrhea, constipation, unintentional weight loss, blood in the stool or heartburn with your gas.