Health Information Library

Overview

Gas in your digestive system is part of the normal process of digestion. Getting rid of excess gas, either by burping or passing gas (flatus), also is normal. Gas pain may occur if gas is trapped or not moving well through your digestive system.

An increase in gas or gas pain may result from eating foods that are more likely to produce gas. Often, relatively simple changes in eating habits can lessen bothersome gas.

Certain digestive system disorders, such as irritable bowel syndrome or celiac disease, may cause — in addition to other signs and symptoms — an increase in gas or gas pain.

Symptoms

Signs or symptoms of gas or gas pains include:

• Burping
• Passing gas
• Pain, cramps or a knotted feeling in your abdomen
• A feeling of fullness or pressure in your abdomen (bloating)
• An observable increase in the size of your abdomen (distention)

Burping is normal, particularly during or right after a meal. Most people pass gas up to 20 times a day. Therefore, while having gas may be inconvenient or embarrassing, burping and passing gas are rarely by themselves a sign of a medical problem.

When to see a doctor

Talk to your doctor if your gas or gas pains are so persistent or severe that they interfere with your ability to function well in daily life. Gas or gas pains accompanied by other signs or symptoms may indicate more-serious conditions. See your doctor if you experience any of these additional signs or symptoms:

• Bloody stools
• Change in consistency of stools
• Change in frequency of bowel movements
• Weight loss
• Constipation or diarrhea
• Persistent or recurrent nausea or vomiting

Seek immediate care if you experience:

• Prolonged abdominal pain
• Chest pain

Causes

Gas in your stomach is primarily caused by swallowing air when you eat or drink. Most stomach gas is released when you burp.

Gas forms in your large intestine (colon) when bacteria ferment carbohydrates — fiber, some starches and some sugars — that aren't digested in your small intestine. Bacteria also consume some of that gas, but the remaining gas is released when you pass gas from your anus.

Common foods that cause gas

Certain high-fiber foods may cause gas, including:

• Beans and peas (legumes)
• Fruits
• Vegetables
• Whole grains

While high-fiber foods increase gas production, fiber is essential for keeping your digestive tract in good working order and regulating blood sugar and cholesterol levels.

Other dietary factors

Other dietary factors that can contribute to increased gas in the digestive system include the following:

• Carbonated beverages, such as soda and beer, increase stomach gas.
• Eating habits, such as eating too quickly, drinking through a straw, chewing gum, sucking on candies or talking while chewing results in swallowing more air.
• Fiber supplements containing psyllium, such as Metamucil, may increase colon gas.
• Sugar substitutes, or artificial sweeteners, such as sorbitol, mannitol and xylitol, found in some sugar-free foods and beverages may cause excess colon gas.

Medical conditions

Medical conditions that may increase intestinal gas, bloating or gas pain include the following:

• Chronic intestinal disease. Excess gas is often a symptom of chronic intestinal conditions, such as diverticulitis, ulcerative colitis or Crohn's disease.
• Small bowel bacterial overgrowth. An increase or change in the bacteria in the small intestine can cause excess gas, diarrhea and weight loss.
• Food intolerances. Gas or bloating may occur if your digestive system can't break down and absorb certain foods, such as the sugar in dairy products (lactose) or proteins such as gluten in wheat and other grains.
• Constipation. Constipation may make it difficult to pass gas.

Diagnosis

Your doctor will likely determine what's causing your gas and gas pains based on:

• Your medical history
• A review of your dietary habits
• A physical exam

During the physical exam, your doctor may touch your abdomen to determine if there is any tenderness and if anything feels abnormal. Listening to the sound of your abdomen with a stethoscope can help your doctor determine how well your digestive tract is working.

Depending on your exam and presence of other signs and symptoms — such as weight loss, blood in your stool or diarrhea — your doctor may order additional diagnostic tests.

Treatment

If your gas pains are caused by another health problem, treating the underlying condition may offer relief. Otherwise, bothersome gas is generally treated with dietary measures, lifestyle modifications or over-the-counter medications. Although the solution isn't the same for everyone, with a little trial and error, most people are able to find some relief.

Diet

Dietary changes may help reduce the amount of gas your body produces or help gas move more quickly through your system. Keeping a diary of your diet and gas symptoms will help your doctor and you determine the best options for changes in your diet. You may need to eliminate some items or eat smaller portions of others.

Reducing or eliminating the following dietary factors may improve gas symptoms:

• High-fiber foods. High-fiber foods that can cause gas include beans, onions, broccoli, Brussels sprouts, cabbage, cauliflower, artichokes, asparagus, pears, apples, peaches, prunes, whole wheat and bran. You can experiment with which foods affect you most. You may avoid high-fiber foods for a couple of weeks and gradually add them back. Talk to your doctor to ensure you maintain a healthy intake of dietary fiber.
• Dairy. Reducing dairy products from your diet can lessen symptoms. You also may try dairy products that are lactose-free or take milk products supplemented with lactase to help with digestion.
• Sugar substitutes. Eliminate or reduce sugar substitutes, or try a different substitute.
• Fried or fatty foods. Dietary fat delays the clearance of gas from the intestines. Cutting back on fried or fatty foods may reduce symptoms.
• Carbonated beverages. Avoid or reduce your intake of carbonated beverages.
• Fiber supplements. If you use a fiber supplement, talk to your doctor about the amount and type of supplement that is best for you.
• Water. To help prevent constipation, drink water with your meals, throughout the day and with fiber supplements.

Over-the-counter remedies

The following products may reduce gas symptoms for some people:

• Alpha-galactosidase (Beano, BeanAssist, others) helps break down carbohydrates in beans and other vegetables. You take the supplement just before eating a meal.
• Lactase supplements (Lactaid, Digest Dairy Plus, others) help you digest the sugar in dairy products (lactose). These reduce gas symptoms if you're lactose intolerant. Talk to your doctor before using lactase supplements if you're pregnant or breast-feeding.
• Simethicone (Gas-X, Mylanta Gas Minis, others) helps break up the bubbles in gas and may help gas pass through your digestive tract. There is little clinical evidence of its effectiveness in relieving gas symptoms.
• Activated charcoal (Actidose-Aqua, CharcoCaps, others) taken before and after a meal may reduce symptoms, but research has not shown a clear benefit. Also, it may interfere with your body's ability to absorb medications. Charcoal may stain the inside of your mouth and your clothing.

Self care

Making lifestyle changes may help reduce or relieve excess gas and gas pain.

• Try smaller portions. Many of the foods that can cause gas are part of a healthy diet. Try eating smaller portions of problem foods to see if your body can handle a smaller portion without creating excess gas.
• Eat slowly, chew your food thoroughly and don't gulp. If you have a hard time slowing down, put down your fork between each bite.
• Avoid chewing gum, sucking on hard candies and drinking through a straw. These activities can cause you to swallow more air.
• Check your dentures. Poorly fitting dentures can cause you to swallow excess air when you eat and drink. See your dentist if they aren't fitting correctly.
• Don't smoke. Cigarette smoking can increase the amount of air you swallow. Talk to your doctor if you need help quitting.
• Exercise. Regular exercise reduces the risk of constipation, which can prevent the release of gas from your colon.

If the odor from passing gas concerns you, limiting foods high in sulfur-containing compounds — such as broccoli, Brussels sprouts, cabbage, cauliflower, beer and foods high in protein — may reduce distinctive odors. Pads, underwear and cushions containing charcoal also may help absorb unpleasant odors from passing gas.

Preparing for your appointment

Before you see your doctor be prepared to answer the following questions:

• How long have you noticed an increase in gas or gas pains?
• Does the pain go away or get better when you belch or pass gas?
• How many times do you pass gas each day?
• Do certain foods seem to trigger your symptoms?
• Have you added any new foods or drinks to your diet recently?
• What medications or dietary supplements do you take?
• Do you have nausea or vomiting with your gas pains?
• Have you lost weight unintentionally?
• Have you had a change in your bowel habits?
• Do you drink sodas or other carbonated beverages?
• Do you eat food with sugar substitutes?
• Do you frequently chew gum, suck on candies or drink through a straw?

What you can do in the meantime

Keep a journal of what you eat and drink, how many times a day you pass gas, and any other symptoms you experience. Bring the journal to your appointment. It can help your doctor determine whether there's a connection between your gas or gas pains and your diet.