Most people experience abdominal swelling or bloating at some point, due to various causes. It feels as though the stomach has expanded and stretched, which can be uncomfortable.
Having too much to eat or consuming food that causes gas can cause temporary swelling in the stomach. However, if the swelling is frequent, it may indicate a dietary issue or be a sign of a more serious underlying condition.
Below are some of the possible causes of a swollen stomach, along with their treatment options:
Irritable bowel syndrome
Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder that causes symptoms such as:
- stomach pain or discomfort
- constipation or diarrhea
According to the American College of Gastroenterology (ACG), the cause of IBS is unknown. However, the ACG note that people with IBS tend to have higher levels of sensitivity in the intestines than those who do not have the condition.
There is no cure for IBS. However, the following home treatments may help alleviate the symptoms:
- avoiding or limiting gas-producing foods, such as:
- fructose, a fruit sugar
- lactose, a milk sugar
- carbonated drinks
- sugar substitutes, such as sorbitol and mannitol
- eating foods more slowly
- avoiding overeating
- introducing more fiber into the diet, but doing so gradually to avoid aggravating bloating
Some medical treatment options include:
- antidiarrheal drugs to reduce the frequency of bowel movements, in people with diarrhea
- laxatives to promote bowel movements, in people with constipation
- medications to relieve pain
Lactose intolerance is a digestive disorder in which a person is unable to digest the sugar lactose, which is present in milk.
A person with lactose intolerance will develop uncomfortable or painful symptoms within a few hours of consuming milk or dairy products. These symptoms may include:
- stomach bloating
- stomach cramps and pains
- stomach rumbling
The severity of the symptoms varies depending on how much lactose a person has consumed.
The best way to prevent the symptoms of lactose intolerance is to avoid foods and beverages that contain lactose.
Alternatively, people can try taking lactase pills or capsules before eating a meal that contains lactose. The enzyme lactase helps the body digest this sugar.
Some of the causes of stomach bloating are more serious. They include those below:
Cirrhosis is a condition in which functioning liver cells become replaced with nonfunctioning scar tissue. Liver scarring can cause increased blood pressure in the blood vessels surrounding the liver. This, in turn, can cause fluid to accumulate in the abdomen.
The causes of liver disease range from underlying medical conditions to the long-term overconsumption of alcohol.
The treatment approach for cirrhosis depends on its underlying cause. In most cases, it is not possible to cure cirrhosis. However, the following lifestyle changes can help a person manage their symptoms while preventing the disease from progressing:
- avoiding alcohol
- quitting smoking
- losing weight, if necessary
- performing regular exercise to maintain muscle mass
- practicing good hygiene to reduce the risk of infections
- talking to a doctor about any necessary vaccinations
People can reduce stomach swelling by cutting salt out of their diet. They can also take a diuretic to help fluid drain from the body.
In people with autoimmune diseases, the immune system mistakenly attacks and destroys healthy cells in the body.
Autoimmune atrophic gastritis (AAG) is an autoimmune disease in which the immune system destroys parietal cells in the stomach. These cells make stomach acid, which the body requires to absorb vitamin B12. In AAG, the gradual loss of parietal cells can lead to iron deficiency and vitamin B12 deficiency.
The possible symptoms of AAG include:
- a feeling of fullness in the upper abdomen after eating
- stomach pain
The cause of AAG is unclear, but people may be at higher risk if they have:
- autoimmune thyroiditis
- type I diabetes
- Addison’s disease — an endocrine disorder
- vitiligo, which is a lack of melanin in areas of the skin
Scientists also believe that the condition might have a genetic factor, as it seems to be heritable.
The treatment for AAG involves addressing any nutrient deficiencies. People with iron deficiency may require intravenous iron infusions, while those with vitamin B12 deficiency may require vitamin B12 injections.
Congestive heart failure
Congestive heart failure (CHF) is a disease that reduces the heart’s ability to pump blood around the body. This impairment causes blood to build up in the chest. The fluid may then seep down into the abdomen, causing stomach swelling.
Other possible symptoms of CHF include:
- persistent coughing or wheezing
- shortness of breath
- increased heart rate
- lack of appetite
- impaired thinking
Congestive heart failure generally develops as a result of other conditions, such as high blood pressure and coronary artery disease.
The treatment for CHF may involve one or more of the following:
- lifestyle changes, such as:
- quitting smoking, if relevant
- avoiding or limiting alcohol and caffeine
- being physically active
- eating a heart-healthy diet
- managing stress
- medications, such as:
- angiotensin converting enzyme (ACE) inhibitors
There are many other possible reasons why a person’s stomach might swell. According to the International Foundation for Gastrointestinal Disorders, these reasons include:
- high salt intake
- hypersensitivity to the digestive process
- imbalance of gut microbiota
- small intestinal bacterial overgrowth (SIBO)
- a blockage in the intestine
- an increased curvature at the bottom of the spine, which reduces the space for gas in the abdomen
- edema due to some types of cancer or cancer treatment
If a person experiences severe or persistent stomach swelling, their doctor may run one or more of the following tests to identify the cause:
- fecal analysis
- blood tests
- abdominal X-rays
- barium swallow test, which uses X-rays to image the esophagus (food pipe) while a person swallows food
- barium enema, which uses X-rays to image the lower intestinal tract
- gastric emptying scan, which is a test to determine how quickly food exits the stomach
- endoscopy of the upper gastrointestinal (GI) tract, which involves the use of a flexible scope to image the upper GI tract
The effective treatment of stomach swelling usually requires the identification and treatment or management of the underlying cause. However, people may also benefit from some general strategies to help ease the swelling.
If a person believes that their stomach swelling is related to their diet, they may wish to try the low FODMAP diet. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Foods that are high in FODMAPS commonly cause gas or abdominal pressure. By removing high FODMAP foods from their diet, a person may reduce the frequency or severity of stomach bloating.
Some medical treatments that may help reduce stomach swelling include:
- antispasmodics to reduce muscle spasms
- probiotics to help redress the balance of good and bad bacteria in the gut
- prokinetics to control acid reflux
- rifaximin (Xifaxan) to restrict the growth of diarrhea-causing bacteria
A person should see their doctor if they experience severe, persistent, or recurrent stomach swelling, especially if other symptoms accompany the swelling.
The outlook for a person with a swollen stomach depends entirely on the cause. People can talk to a doctor for information on their individual treatment options and outlook.
If the stomach regularly swells after a meal, a person should consider eliminating gas-producing foods from their diet. Foods that cause gas include:
- food that contains starch, such as potatoes
- beans, particularly pinto or baked beans
- Brussels sprouts
- carbonated drinks
There are many potential causes of stomach swelling. Some are relatively benign and transient and may be related to a person’s diet. Others may indicate an underlying health condition that requires treatment.
A person should see their doctor if they experience severe, persistent, or recurrent stomach swelling. A doctor will work to diagnose the cause and provide appropriate treatments.