What is abdominal distension?

A distended abdomen is measurably swollen beyond its normal size. It’s often accompanied by the feeling of being bloated with trapped gas or digestive contents. However, abdominal distension isn’t always from digestive processes. Healthcare providers diagnose a distended abdomen in terms of the “five ‘f’s”: flatus (gas), fetus (pregnancy), feces (trapped poop), fluid (from several causes) or fat.

A distended abdomen may be very uncomfortable, or it may simply be a symptom that you and your healthcare provider observe visually. It may be acute — a sudden, unusual occurrence — or chronic — something that occurs and resolves itself repeatedly in a predictable way. Chronic abdominal distension accompanied by an uncomfortable bloated feeling is often related to a digestive problem.

What does abdominal distension indicate?

A distended abdomen is either an organic or a functional problem. An organic problem can be explained by physical evidence, like a disease. Functional problems are observable but unexplained.

Organic causes

Organic causes of abdominal distension might include:

• Pregnancy.
• Menstruation, which causes water retention.
• Significant recent weight gain, which tends to be stored as intra-abdominal fat and may restrict digestion.
• An obstruction of the small or large bowel, causing a build-up of gas and waste matter.
• Partial paralysis of the stomach (gastroparesis) causing a build-up of digestive contents.
• Certain gastrointestinal diseases cause gas and bloating, including small intestinal bacterial overgrowth (SIBO), celiac disease, exocrine pancreatic insufficiency (EPI) and inflammatory bowel diseases (IBD).
• Inflammation of the abdominal lining (peritonitis).
• A build-up of fluid in the abdomen caused by liver disease (ascites).
• Organ enlargement from inflammation or a growth.
• Internal bleeding (intra-abdominal hemorrhage).

Functional causes

Functional reasons for a distended abdomen tend to involve digestive problems that cause gas and/or digestive contents to accumulate. Causes might include:

• Gas from functional indigestion, food intolerances or irritable bowel syndrome (IBS).
• Constipation causing a build-up of feces and back-up of digestive contents.
• Urinary retention causing a build-up of urine.
• A disorder of the muscle contractions involved in digestion (intestinal pseudo-obstruction), causing digestive contents to back up.
• Abdominal muscle weakness, which causes the abdominal contents to sag outwards and downwards (enteroptosis).

How do healthcare providers treat abdominal distension?

If you seek medical care for your distended abdomen, your healthcare provider will work to isolate the cause. They’ll start by asking you questions about your symptoms and examining your abdomen to see where it’s distended. The location of the outward curve, whether it’s uniform across your abdominal cavity or more pronounced in a particular region, helps them determine which organs are involved and narrow down the list of likely causes. They may also feel the area with their hands or tap it and listen to the sound it makes to determine the presence of fluids, gasses or solids.

The internal organs of the abdomen can be classified as either solid or hollow. Solid organs include the liver, spleen, kidneys, adrenals, pancreas, ovaries and uterus. These can become enlarged due to inflammation or growths such as a tumor, abscess or cyst. Your healthcare provider might be able to feel that they are enlarged, or they might need to look at an image of the internal organs to tell. A large growth might be palpable through the skin. Your healthcare provider will confirm your condition with imaging tests, then follow up with additional testing and treatment depending on the condition.

The hollow organs of the abdomen include the stomach, small intestine, colon, gallbladder, bile ducts, fallopian tubes, uterus and bladder. These organs are only palpable if they are distended. If your healthcare provider can feel any of them, they’ll know immediately where the problem is. Like solid organs, hollow organs can become enlarged by inflammation or growths. But they can also become swollen with the products of digestion —gas, digestive juices, poop and urine — or with pregnancy, in the case of the uterus — or, rarely, with internal bleeding. Imaging tests will clarify this.

Another cause of abdominal distension is fluid build-up in the lining of the abdominal cavity, called the peritoneum. These tissues can become inflamed from infection (peritonitis), or they can be filled with fluid as a result of a condition called ascites. Usually a side-effect of liver scarring (cirrhosis), ascites occurs when pressure on the blood vessels in the liver (portal hypertension) forces fluid into the abdominal cavity. Healthcare providers can often identify fluid in the peritoneum from a physical exam, but an abdominal ultrasound is more sensitive.

How do you fix a distended abdomen?

If your distended abdomen has an organic cause, the treatment will be very specific to that cause. It might mean managing a disease, infection, growth, obstruction, or injury. An acute case will resolve when the underlying cause has been treated. A chronic case may be treated supplementally with diuretics (for fluid), laxatives (for constipation) or activated charcoal capsules (for gas).

If you have functional abdominal distension and the cause is unknown, it might take some trial and error to manage it. Your healthcare provider may recommend a hydrogen breath test to help determine the cause of excess intestinal gas. They might also recommend you try dietary changes, probiotics or enzymes to improve digestive processes. If they suspect muscle weakness as a cause, they might suggest abdominal or pelvic floor exercises.

What can I do at home to prevent abdominal distension?

Prevention is easier if you know the cause. If you notice that abdominal distension occurs after you eat, you may be able to change your eating habits to prevent it. For example:

• Identify food sensitivities and change your diet accordingly.
• Eat smaller amounts more slowly. Wait longer between meals.
• Drink more water and eat more fiber to prevent the accumulation of waste.
• Try digestive enzymes and probiotics before meals.

When should I be concerned about a distended abdomen?

Seek medical care if your abdominal distension:

• Keeps getting worse and doesn’t go away.
• Comes with severe abdominal pain.
• Comes with symptoms of illness, such as fever, vomiting or bleeding.
• Is a chronic problem and you don’t know the cause.