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.
Signs or symptoms of gas or gas pains include:
- 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
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)
- 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 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.