Excessive Gas and IBS

Reviewed by: HU Medical Review Board | Last reviewed: May 2023 | Last updated: May 2023

Many people with irritable bowel syndrome (IBS) have excessive gassiness (flatulence). Excess gas can be embarrassing and uncomfortable. And the resulting stress can have a negative impact on a person’s quality of life and productivity.1

It is not clear why IBS causes excessive gas. Actually, it seems that most people with IBS do not produce more gas but are simply more aware of normal amounts of gas.1,2

Treating excessive gas is hard because no single treatment works for everyone. Foods that give someone else gas may not bother you. And treatments that relieve gas for someone else may not help you. Talk to your doctor to determine the right treatment for you.2

What causes excessive gas?

Passing gas is completely normal. In fact, the average person passes gas 14 to 23 times per day. Burping occasionally during and after meals is also normal.2-4

The amount of gas you produce depends on your diet and other individual factors. There are 2 main sources of gas in the intestine: swallowed air and bacteria produced in the gut.2-4

Air swallowing

It is normal to swallow a small amount of air when eating and drinking. You may swallow more air if you eat quickly, gulp liquids, chew gum, or smoke. Burping removes most air, but a small amount may pass from the stomach to the small intestine.2-4

Bacterial production

Your colon contains bacteria that support healthy bowel movements. However, some carbohydrates (sugars, starches, and fibers) are not fully digested in the stomach and intestines. These foods must be broken down by bacteria in the colon. During this process, bacteria produce odorless gases like carbon dioxide and methane. They also produce small amounts of smelly gases like sulfur.2-4

You should talk to your doctor if your gas symptoms bother you or change suddenly, or if you also have other IBS symptoms.

Why does IBS cause excessive gas?

Many people with IBS feel they have excessive gas or burp too much. But most people bothered by gas symptoms do not actually have more gas in their intestines. Instead, they are more sensitive to normal amounts of gas. They feel the gas and discomfort from it more than someone without IBS. The medical term for this increased sensitivity is visceral hypersensitivity.1,2,5

Experts do not know why IBS causes this increased sensitivity in the intestines. One theory is that nerves carrying messages from the bowel are hyperactive in people with IBS. This causes normal amounts of gas to be more painful. Some people feel better when they take medicines that decrease pain perception in the intestines.1,2,5

Many foods can worsen IBS gas symptoms, especially ones that contain specific carbohydrates called FODMAPs (fermentable oligo-, di-, and monosaccharides and polyols). FODMAPs are found in wheat, barley, milk, and certain fruits and vegetables.2,4-6

How is excessive gas treated?

There are many ways to treat excessive gas, but it sometimes takes trial and error to figure out what works for you. Talk with your doctor about your symptoms and stressors.2

The first treatment is often changing your diet to avoid foods that aggravate gas. Talk to your doctor if you want to try avoiding certain foods. They can advise you about what to limit and how to get enough nutrients. Keeping a food diary to monitor your diet and bowel movements can help identify foods that give you gas.2

Many people with IBS respond well to a low FODMAP diet. Some examples of high FODMAP foods that these people cut out for a while are:2,6,7

  • Grains: wheat, rye, and barley
  • Fruits: apples, apricots, blackberries, cherries, dates, grapefruits, mangos, pears, and watermelons
  • Vegetables: artichokes, asparagus, broccoli, Brussels sprouts, cauliflower, garlic, leeks, mushrooms, and onions
  • Dairy: coconut milk, ice cream, milk, cheese, soy milk, and yogurt
  • Proteins: most beans, legumes, and processed meats
  • Beverages: high-fructose sodas and juices

A low FODMAP diet can help lessen symptoms in most people with IBS. But staying on a low FODMAP diet for a long time is not always a good idea. Work with your doctor or a dietitian to slowly phase certain foods back into your diet to determine which ones you can tolerate. This will create a personalized low FODMAP diet that works for you.6,7

There are also over-the-counter medicines that may reduce gas. Products that contain simethicone (such as certain antacids) are widely used to relieve gas. Digestive enzymes, such as lactose supplements, may help as well.2,3

Many prescription drugs are also available that may treat IBS gas. They are usually recommended only if diet changes do not work. Probiotics and antibiotics are also sometimes used to support intestinal bacteria that produce less gas.1,5

Treatment is usually best with an approach that combines diet and lifestyle changes, exercise, and medicines. Talk to your doctor to find the right combination that works for you.5,7

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