Gas and Gas Pain

Overview

What is intestinal gas?

Intestinal gas is a mix of odorless vapors, including oxygen, carbon dioxide, nitrogen, hydrogen and methane. This gas forms in the digestive system. When these vapors mix with intestinal bacteria, an unpleasant sulfur odor can develop.

Your body releases gas through the mouth (belching) or rectum (flatulence). Sometimes gas gets trapped in the stomach. This gas buildup causes abdominal pain and bloating (a swollen or tight feeling).

How common is intestinal gas?

Intestinal gas is a fact of life — a natural result of food digestion. Everyone feels gassy now and then. Studies suggest that most people pass gas (fart) up to 21 times per day.

Symptoms and Causes

What causes intestinal gas?

Causes of intestinal gas include:

  • Food digestion: Your small intestines lack certain enzymes needed to digest and absorb carbohydrates (sugars) in sweet, starchy and fibrous foods. This undigested food passes into the large intestine, where harmless bacteria break down the food, forming hydrogen and carbon dioxide gases. In some people, intestinal bacteria produce methane gas, too. This process is responsible for most gas passed in flatulence.
  • Swallowing air: You swallow air (containing oxygen, nitrogen and carbon dioxide) without even noticing while eating, drinking, chewing gum or smoking. You can also swallow too much air if you have loose-fitting dentures. Most people expel swallowed air through the mouth by belching (burping). But your intestines partially absorb some air, which you pass when you fart.

Who might get intestinal gas?

Excess gas can make your stomach feel swollen or bloated. You may pass flatulence (sometimes foul smelling). Though uncomfortable, excess gas is rarely a concern. Things that make you produce too much gas include:

  • Behavioral factors, such as swallowing air while chewing, drinking and talking.
  • Dietary choices, such as consuming too many gas-producing foods (beans, potatoes, corn, onions, apples and high-fiber products).
  • Digestive problems, such as irritable bowel syndrome (IBS), lactose intolerance and celiac disease.
  • Intestinal infections, such as giardiasis, that cause an overgrowth of intestinal bacteria.
  • Medications or motility disorders that slow the bowels, such as IBS, diabetes and scleroderma.

What are the symptoms of intestinal gas?

Gas symptoms vary depending on the cause. Some typical symptoms of intestinal gas are:

  • Belching (burping).
  • Bloating.
  • Flatulence (farting).

What are the signs of an intestinal gas problem?

You should contact your healthcare provider if you experience gas along with:

Diagnosis and Tests

How is intestinal gas diagnosed?

Your healthcare provider may ask you to keep a food diary for a week or more to see if certain foods or drinks make you gassy. Because excessive gas can be a sign of a health problem, you may need one or more of these tests:

  • Blood tests: These tests detect certain conditions like celiac disease that cause gas.
  • Breath test: A hydrogen breath test identifies lactose intolerance or abnormal bacterial growth in the intestine.
  • Colon screening: A flexible sigmoidoscopy lets your provider view the lower part of your colon and rectum (lower intestine). With a colonoscopy, the provider views all of the large intestine. These tests help identify digestive disorders like Crohn’s disease as well as colon cancer.
  • Food elimination: Your healthcare provider may suggest removing certain foods to see if gas symptoms improve. For example, if you’re less gassy after cutting out dairy, you might be lactose intolerant — unable to break down lactose, a sugar in milk.
  • Gastrointestinal (GI) tract exam: If you belch a lot, your provider may perform a gastrointestinal exam called an upper GI test or barium swallow. You swallow a solution that coats the esophagus, stomach and part of the small intestine with barium for easier viewing on X-rays.

Management and Treatment

How is intestinal gas managed or treated?

By treating a health condition that causes excessive gas, you can enjoy better health. For occasional gas, your healthcare provider might suggest one of these over-the-counter products:

  • Alpha-galactosidase (Beano®), an enzyme to break down hard-to-digest foods.
  • Bismuth subsalicylate (Pepto-Bismol®) for adults with upset stomach and diarrhea.
  • Lactase enzymes (Lactaid®) for lactose intolerance (a problem digesting milk sugars).
  • Probiotics (Culturelle®) to get rid of bad gut bacteria.
  • Simethicone (Gas-X®, Mylanta®) to reduce intestinal gas buildup that causes bloating.

Prescription medications may help if you have a motility problem like IBS. Antibiotics can treat bacterial overgrowth in the intestines that cause excess gas and bloating.

What are the complications of intestinal gas?

Extra gas can cause pain, discomfort and embarrassment, but it’s usually not a serious health problem. Gas buildup can sometimes feel more worrisome, though. Gas on the left side of the colon can cause chest pain that you might mistake for a heart attack. Gas buildup on the right side can mimic pain from gallstones or appendicitis. A health professional should check out these symptoms for any concerning underlying cause.

Prevention

How can I prevent intestinal gas?

Most foods containing carbohydrates can cause gas. A food diary can help you determine which foods make you gassy. But don’t cut out too many things. Many vegetables, fruits, dairy products, wheat products and beans cause gas, but they’re also very good for you.

To reduce your body’s gas production, you can:

  • Chew slowly, and don’t talk while eating.
  • Cut back on carbonated beverages, chewing gum and hard candies.
  • Drink through a straw.
  • Limit certain sugars, including fructose, sucrose, sorbitol and raffinose.
  • Stop smoking.

Living With

When should I call the doctor?

You should call your healthcare provider if you experience:

  • Chest pain or signs of heart attack.
  • Gastrointestinal discomfort not associated with eating.
  • Severe abdominal pain, diarrhea or constipation.
  • Tarry, black stool or rectal bleeding.
  • Unexplained weight loss.

What questions should I ask my doctor?

You may want to ask your healthcare provider:

  • Could a medical condition be making me gassy?
  • What tests can determine the cause of intestinal gas?
  • What steps can I take to cut down on intestinal gas?
  • What foods or drinks should I avoid?
  • What’s the best treatment for my gas symptom?
  • How can I tell the difference between gas and something more serious?
  • Should I look out for signs of complications?

A note from Cleveland Clinic

While intestinal gas is common, the symptoms — belching, flatulence, bloating and stomach discomfort — can be embarrassing and even painful. Gas is sometimes a symptom of a more serious health problem. Talk to your healthcare provider about your concerns. The right treatment can ease gas symptoms so you can go about your day in confidence.

Last reviewed by a Cleveland Clinic medical professional on 09/11/2020.

References

  • American College of Gastroenterology. Belching, Bloating and Flatulence. (https://gi.org/topics/belching-bloating-and-flatulence/) Accessed 10/18/2021.
  • American Family Physician. Gas, Bloating and Belching. (https://www.aafp.org/afp/2019/0301/p301-s1.html) Accessed 10/18/2021.
  • National Institute of Diabetes and Digestive and Kidney Disorders. Symptoms and Causes of Gas in the Digestive Tract. (https://www.niddk.nih.gov/health-information/digestive-diseases/gas-digestive-tract/symptoms-causes) Accessed 10/18/2021.

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