What Is Bloating?

Distention of the Stomach Caused By Overeating or Gas

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Bloating is distention (protrusion) of the abdomen, often accompanied by an uncomfortable feeling of fullness or tightness. Although it can cause your stomach to appear larger than normal and your clothing to feel tight around your waist, bloating is not caused by excess abdominal fat. Most often it occurs after eating a large meal, but also is associated with gluten intolerance, the build-up of digestive gasses, or, if you menstruate, the accumulation of fluid during your period. Effectively preventing or relieving belly bloat depends on what causes it. It often can be prevented by measures such as changing eating habits or taking medication to prevent or relieve gas.

What Is Bloating?

Bloating is distention of the abdomen that can cause your belly to look and feel larger than normal. It is not caused by excess fat, but rather by overeating, the accumulation of gas, or extra fluid that occurs during menstruation.

Causes

Most often bloating is linked to eating habits or certain foods and beverages that cause the build-up of gasses in the digestive system—among them, carbon dioxide, oxygen, nitrogen, hydrogen, and sometimes methane or sulfur (which is responsible for the unpleasant odor when gas is released).

Food-related causes of bloating include:

  • Eating too much: Stomach tissue is stretchy: If you put more into it than it can easily accommodate it will stretch enough to protrude.
  • Eating too fast: Consuming food without taking a break doesn't give your belly and your brain time to acknowledge the signs of (satiety) fullness. By the time your body catches up, 15 or 20 minutes after you've eaten, you may feel as if you've downed two or three meals rather than one.
  • High-fiber foods: Whole grains and other foods that are rich in fiber can cause bloating, especially if you aren't used to eating them.
  • Constipation. Stool backed up in the bowels can cause distention of the lower abdomen.
  • Swallowing air: When you chew gum or drink carbonated beverages, you're essentially consuming air. The same holds for drinking from a straw.
  • Drinking: Alcohol of any type may cause temporary puffiness by irritating the lining of the stomach. Bubbly beverages (beer, champagne, cocktails mixed with soda) can be especially problematic. People who abuse alcohol may develop a condition called alcoholic gastritis—inflammation that tends to flare after a binge, causing bloating and other symptoms.
  • Lactose intolerance: People who are lactose intolerant do not have lactase, the enzyme needed to digest the sugar in dairy products, and as a result experience nausea and bloating within 30 minutes to 2 hours after consuming foods such as milk or cheese.
  • Gluten: Some people who are sensitive to gluten (a protein found in wheat and other grains) or who have celiac disease may experience gas and bloating after eating foods with gluten.
  • Irritable bowel syndrome (IBS): Some foods, such as artificial sweeteners, certain fruits and vegetables, and or dairy products may produce uncomfortable gas and discomfort in some people.

The hormonal fluctuations that occur during menstruation can affect fluid levels in the body. Bloating is common during a person's period and is a key symptom of premenstrual syndrome.

Symptoms

The most obvious symptom of bloating is visual: Your stomach will appear to "stick out" and look rounded and the skin of your abdominal region may feel stretched and taut. Belly bloating can even interfere with how your clothing fits around the waist, sometimes to the extent you want to loosen your belt, unbutton the top button on your pants, or change into sweats.

Depending on the cause, bloating may be accompanied by discomfort, stomach growling or rumbling, nausea, or gassiness (flatulence and/or burping).

Abdominal bloating will persist until the food in an overfull stomach is digested or accumulated gas is expelled.

Prevention

The most effective way to deal with bloating is through diet and lifestyle changes. If you can identify the food or eating behavior that causes belly bloat, you can avoid them and effectively prevent bloating.

  • Don't eat too much. Don't supersize servings: Keep meal and snack portions moderate. Better to have seconds than to stuff yourself.
  • Eat slowly and savor each bite. Gulping your food will prevent you from knowing when you're full until it's too late and also can introduce air into your body.
  • Avoid foods that make you gassy. This may include greasy fried foods, sugar substitutes, and any ingredients you're allergic to or sensitive to.
  • Add fiber slowly. Healthy fiber-rich foods can help you to feel full (making them helpful if you're trying to lose weight), but they can also cause gas and bloating if you aren't used to eating them. Add them to your diet slowly.
  • Avoid carbonated beverages. The bubbles in carbonated drinks are gas, which is why you can feel bloated after drinking them.

Treatment

When despite your best efforts to stave off bloating you experience it anyway, there are over-the-counter (OTC) medications that can quell the swelling and ease discomfort.

  • Antacids, such as Mylanta II, Maalox II, and Di-Gel, contain simethicone, which adheres to bubbles in the stomach so that gas is more easily belched out.
  • Activated charcoal tablets may provide relief from gas in the colon.
  • Lactaid, Lactrase, and Dairy Ease contain lactase, which can help prevent gas for people with lactose intolerance.
  • Pepto-Bismol (bismuth subsalicylate) may help reduce bloating caused by an upset stomach.
  • Beano or Gas-Zyme 3x are OTC products that contain an enzyme called alpha-galactosidase that breaks down complex carbohydrates in gassy foods into more digestible sugars before they reach the colon. This helps prevent gas before it starts.
  • Probiotics are "good" bacteria that help to maintain the health of the microbiome in the digestive system. They can be found in foods such as yogurt as well as in OTC supplements.
  • Movement and massage. Gentle exercise (a walk around the block, say, or a yoga class) can help to get gasses in the digestive system moving. Certain types of massage may be beneficial as well.

When to See a Doctor

Bloating is rarely a sign of a serious medical problem. However, bloating that is chronic and doesn't respond to changes in eating habits or OTC treatments sometimes is associated with certain diseases and conditions.

Bloating that is accompanied by abdominal pain, bloody stools, persistent diarrhea, or vomiting are especially concerning and can be a sign of any of a number of serious diseases and conditions, including colon cancer, bowel obstruction, celiac disease, and irritable bowel syndrome (IBS).

If you notice you're frequently or constantly bloated or that you become bloated after eating certain foods—especially those that contain wheat or dairy—make an appointment to see your doctor. It will be helpful for them if you jot down when you're most likely to experience bloating and under what circumstances.

A Word From Verywell

There's nothing fun about bloating—especially if it means your clothes aren't uncomfortable, your belly sticks out, or you have embarrassing or annoying symptoms such as flatulence. It rarely is something to worry about, and many of the lifestyle changes that can help to treat or prevent bloating are ones that likely will improve your overall health and well-being and so are worth making.

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Article Sources
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  1. National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & causes of gas in the digestive tract. Updated July 2016.

  2. Sullivan SN. Functional abdominal bloating with distentionISRN Gastroenterol. 2012;2012:721820. doi:10.5402/2012/721820

  3. American Addiction Centers. Alcoholic gastritis symptoms, causes & treatment. Updated Aug 6, 2020.

  4. National Institute of Diabetes and Digestive and Kidney Diseases. Eating, Diet, & Nutrition for Gas in the Digestive Tract. Updated July 2016.

  5. Cleveland Clinic. Gas: Care and treatment. Oct. 25, 2016.

  6. Harvard Health Publishing. Relief from intestinal gas. September 2013.

  7. Treatment for Gas in the Digestive Tract. National Institute of Diabetes and Digestive and Kidney Diseases.

  8. Foley A, Burgell R, Barrett JS, Gibson PR. Management strategies for abdominal bloating and distensionGastroenterol Hepatol (N Y). 2014;10(9):561–571.