Why Am I Gassy? Causes of Gas and Bloating, and How to Change Your Diet

Written by Kelly Elterman, MD | Reviewed by Patricia Pinto-Garcia, MD, MPHUpdated on February 1, 2022.  (from Good Rx)

Key takeaways:

• It’s normal to feel gassy or bloated, but that doesn’t always make it an easy subject to talk about. 
• But no matter how embarrassing gas or bloating can be, rest assured that it’s something we all get — usually from the foods that we eat.
• In some cases, though, too much gas or bloating can be caused by a medical condition, and so it’s important to talk with a healthcare provider if the problem is ongoing.

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Everyone experiences feeling “gassy” from time to time. For some people, having gas means abdominal pain, while for others it means belching or having flatulence. These are normal body functions related to the passage of gas through the gastrointestinal (GI) tract. Sometimes, your diet or a medical condition can cause you to have more gas than usual. 

Here, we’ll explore what it means to be gassy, where gas in your GI tract comes from, and what you can do to feel less gassy.

What does it mean to be ‘gassy’?

Feeling gassy typically means having a sense of abdominal fullness, bloating, or pain. Sometimes, this feeling can also cause more frequent belching or passing of gas. For most people, this feeling typically comes from an increased amount of gas in the GI tract. Some people are sensitive to gas in the GI tract and may develop these symptoms even with a normal amount of gas.

These symptoms can be common for many people after eating certain foods. Usually, they are temporary and people often feel better after passing gas. Sometimes, these symptoms may be a sign of an underlying medical problem. This may be the case if your symptoms of gassiness or bloating are new, very frequent, or continue after you’ve changed your diet. Other signs of a problem are when the gassiness occurs along with nausea, vomiting, or diarrhea. 

Why is there gas in your intestines?

Swallowing air

Gas in the GI tract comes from air that you swallow. Everyone swallows some air all of the time, such as while eating, drinking, or chewing gum. People who have anxiety, chronic post-nasal drip, or wear dentures may swallow more air than other people.

Food

Gas in the GI tract also comes from the food you eat. Carbonated beverages, which contain carbon dioxide, increase gas in the GI tract and often cause people to belch. Foods that contain different kinds of sugars can also increase gas production. This is because, for some people, the small intestine does not digest certain sugars very well. When this happens, these sugars pass into the large intestine where bacteria break them down. As the bacteria break down the sugars, they create gas that can lead to abdominal pain, bloating, and flatulence. 

What causes excessive gas and bloating?

Excessive gas and bloating can come from eating certain foods that are more difficult to digest. For some people, these can include high-fiber foods like leafy greens and beans. There are also some medical conditions (listed below) that can affect GI function and cause increased gas and bloating for some people after eating certain foods.

Irritable bowel syndrome (IBS)

With IBS, the gut may be sensitive to normal or slightly increased amounts of gas.

Gastroesophageal reflux disease (GERD)

GERD is also known as acid reflux, or the return of stomach contents back into the esophagus, and can cause you to belch or feel bloated.

Lactose and fructose intolerance

Lactose intolerance is an inability to break down lactose in the small intestine. People who have lactose intolerance do not have the enzyme needed to break down lactose, which is the sugar found in milk and dairy products. When someone with lactose intolerance consumes dairy, the lactose that they can’t break down passes into the large intestine and bacteria break it down and produce gas. This is why eating dairy can cause abdominal pain, bloating, and flatulence for people with lactose intolerance. 

Similarly, fructose intolerance is an inability to break down fructose in the small intestine. It can cause gas in much the same way as lactose intolerance.

Bacterial overgrowth in the small bowel

Having too much bacteria in your small intestine, or a change in the type of bacteria that is normally there, is known as small bowel bacterial overgrowth, and it can make you feel gassy. 

Celiac disease

Celiac disease is an autoimmune condition that may lead to abdominal pain and bloating after eating foods with gluten.

Constipation

Constipation is when bowel movements are infrequent and difficult to pass. Bloating and gas often accompany constipation. 

Increased air swallowing

As we mentioned, increased air swallowing can also lead to excessive gas and bloating. Risk factors that may increase air swallowing include:

• Anxiety
• Postnasal drip
• Poorly fitting dentures
• GERD
• Smoking
• Chewing gum or sucking on hard candy

When is gas a sign of a more serious problem?

Sometimes, having symptoms of gas can be a sign of a more serious condition that needs urgent medical attention. Examples include: 

• Gastroparesis: This is a condition where the stomach empties slower than normal. It can make you feel gassy, but can also cause significant nausea and vomiting.
• Intestinal obstruction: This is a blockage of a portion of the bowel, and it is a very serious medical condition that needs emergency attention. Intestinal obstruction can cause significant pain, bloating, and vomiting. 

What food and drink should I avoid if I am trying to reduce gas and bloating?

Eating foods that can increase the amount of gas in your GI tract can make you feel bloated or make you belch or pass gas frequently. If you are trying to reduce gas and bloating, there are some dietary changes you can make. 

Carbonated beverages

First, avoid carbonated beverages, like soda, beer, and carbonated water or energy drinks. Try drinking plain water instead. Avoiding carbonated drinks will reduce the amount of gas in your GI tract, and drinking more water can help improve constipation, which can also make you feel less bloated.

FODMAPs

Other foods to avoid include dairy products and foods with fermentable sugars, known as FODMAPs. FODMAPs stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are sugars that, in some people, are not well digested in the small intestine. 

Examples of FODMAPs include:

• Fruits, like apples, pears, peaches, and watermelon
• Honey and agave nectar
• Vegetables, like asparagus, broccoli, and cabbage
• Grains, like wheat and rye
• Beans and lentils
• Artificial sweeteners

Not everyone reacts in the same way to the same FODMAP foods. Some people tolerate some of them better than others. In general, low FODMAP diets are only intended to be followed for a short period of time. If you decide to try avoiding FODMAPs, you can cut them all out for a couple of weeks and then reintroduce one at a time to see if you are able to eat it without getting gassy. 

Talking with a dietician or your primary care provider can help you determine if a low FODMAP diet may be a good idea for you. 

What else can I eat or drink to help reduce gas and bloating?

Besides avoiding certain foods, there are other things you can do to help reduce gas and bloating. 

How you eat

Changing what you eat can help reduce gas, but changing how you eat is also important: 

• Try eating slower, and having smaller but more frequent meals throughout the day. 
• If you can, sit down when eating, rather than eating on the run, and minimize talking while you eat. 
• Sometimes a short walk after eating can help reduce gas. 

OTC medications

There are several over-the-counter medications you can try to treat gas. These medications include activated charcoal, simethicone, and alpha-galactosidase, also known as “Beano.” Activated charcoal and simethicone may work for some people, but current evidence does not show that they are effective treatments. Alpha-galactosidase, however, has been shown to effectively prevent gas related to eating high-fiber foods. 

Identify causes

To avoid gas and bloating, it is important to determine what is causing your symptoms: 

• Some causes, like constipation, may get better with increasing fiber, drinking more water, and doing more physical exercise. 
• If you wear dentures, checking how well they fit and getting them adjusted may help you feel less gassy. 
• Other causes — like lactose intolerance, GERD, or celiac disease — need medical evaluation and treatment. 
• If you’ve tried eliminating foods that make you gassy and that has not helped, make an appointment for a medical evaluation. 

The bottom line

Feeling gassy or bloated is very common. What you eat and how you eat may be causing you to feel gassy. Changing your diet and eating habits can go a long way in helping reduce gas and bloating. If nothing seems to help, it’s important to seek medical care.