Swollen abdomen

A bloated stomach is also called a swollen abdomen and is often accompanied by abdominal pain or stomach cramps. This very common condition is usually short-lived and goes away on its own, sometimes after passing wind (flatulence).

Although everyone has gas in their gut, some people are more sensitive to gas passing through their gut. This can cause symptoms of pain, excessive burping and flatulence. Your stomach may also feel hard, puffy, stretched and uncomfortable, as well as appear swollen.

A bloated stomach is usually nothing to worry about but can be a sign of an underlying health problem. If you have any concerns about a bloated stomach, make an appointment to see your GP.

Your gut always contains gas, most of which comes from swallowing air when you eat and drink. However, gas is also made by bacteria feeding off the food in your gut — certain foods stimulate more gas production by bacteria than others. 

When sitting up, gas in your gut usually passes up through your gullet and out of your mouth (burping). When lying flat, this gas usually passes down into your stomach, which can cause a bloated stomach (abdominal bloating) after eating and a hard, swollen abdomen. Gas can also leave your body by passing wind, commonly known as farting, where gas enters your small intestine and passes out of your back passage (anus).

Several possible health conditions can cause a bloated stomach or swollen abdomen, including:

• A condition affecting the digestive system — this includes: 
• Coeliac disease — your immune system mistakenly attacks your gut tissue when you eat gluten
• Constipation
• Diverticulitis — infection of small pouches (diverticula) in the wall of your bowel
• Irritable bowel syndrome (IBS) — a condition that causes stomach pain and cramps, bloating, gas and a swollen abdomen
• Short bowel syndrome — usually a consequence of surgery to remove significant portions of your bowel, where not enough nutrients can be absorbed from your food via your bowel
• Small intestinal bacterial overgrowth — excessive growth of bacteria that naturally occur in your small intestine
• A food intolerance or an intolerance to certain natural substances eg lactose, fructose or gluten — if you are lactose intolerant, you are unable to digest lactose and, therefore, may develop bloating, gas and a swollen stomach within two hours of eating or drinking lactose which is a sugar found in dairy products
• Ascites — fluid build-up in your abdomen, usually caused by liver problems eg liver cirrhosis where your liver develops a lot of scar tissue; ascites starts without noticeable symptoms but over time your abdomen will become increasingly swollen, which causes discomfort
• Gallstones — hard, fatty lumps in your gallbladder
• Pancreatitis — inflammation of your pancreas
• Scleroderma — an autoimmune condition that causes hardening and tightening of your skin and connective tissue

Some cancers can also cause a bloated stomach, including ovarian cancer. 

Certain lifestyle factors can increase your risk of developing a bloated stomach too, including: 

• Dehydration
• Eating quickly and swallowing too much air, perhaps because you are stressed
• Lack of sleep
• Overeating or eating foods high in fibre or that are otherwise difficult to digest, including beans, Brussel sprouts, broccoli, cabbage, cauliflower and onions 
• Gaining weight
• Stress 

In women, a bloated stomach can also be caused by: 

• Ovarian cysts — fluid-filled sacs in or on your ovaries
• Pregnancy
• Premenstrual syndrome (PMS)

Certain medications can also cause a bloated stomach and excessive flatulence as side effects eg the diabetes medication metformin and the laxative lactulose. 

If you regularly have a bloated stomach or the swelling doesn’t go away, see your GP. You should also contact your GP if you have a swollen abdomen and a fever, difficulty swallowing (dysphagia) and/or any of the following symptoms:

• Abdominal pain or stomach cramps
• Anaemia symptoms ie breathlessness, fatigue, hair loss, heart palpitations, pale skin and weakness
• Blood in your stools
• Diarrhoea or vomiting
• Heartburn
• Lack of appetite and/or unexplained weight loss

Your GP will ask about your general health and any other symptoms you are experiencing and may examine your stomach.

They may refer you for tests, including: 

• Blood tests eg to test for Coeliac disease
• Colonoscopy or endoscopy to examine the inside of your gut using a small camera
• CT scan 
• Lactose tolerance test
• Stool test — a sample of your stools will be checked for microscopic traces of blood, infection and high fat levels; high fat levels may suggest a problem with absorbing food
• X-ray of your gut

They may also refer you to a consultant for further investigations, diagnosis and treatment.

Home remedies

A swollen abdomen can usually be treated at home. It may pass by simply waiting for your food to digest. 

If certain foods appear to trigger your bloating (eg beans, broccoli and cabbage), avoid or reduce how much of these you eat. If you think you have a food intolerance, keeping a food diary can help you identify trigger foods such as dairy products if you are lactose intolerant, or wheat and gluten if you have a gluten sensitivity. However, do not completely cut out an entire food group from your diet as this can adversely affect your health. Instead, speak to your GP or a nutritionist about safely adjusting your diet.

Depending on your other symptoms, you can also try:

• Avoiding carbonated drinks and drinking through a straw to avoid swallowing too much air when drinking
• Changing the way you eat — this includes:
• Chewing your food properly and with your mouth closed to avoid swallowing too much air
• Eating slowly 
• Eating smaller but more frequent meals
• Sitting down when eating without slumping or hunching 
• Reducing the risk of constipation by eating a diet rich in fibre and exercising regularly eg brisk walking for 20-30 minutes four times a week
• Stopping chewing gum to reduce how much air you swallow

If you have ascites, lying down and decreasing the amount of sodium in your diet, which is found in salt, can help reduce the fluid build-up that causes your abdomen to swell. 

If you have coeliac disease, following a gluten-free diet will help. 

If you have IBS, increasing the amount of fibre in your diet and reducing your stress levels may help reduce your stomach bloating. 

Medications

There are several over-the-counter medications and dietary supplements which can relieve a bloated stomach, such as:

• Anti-foaming medication to break up the tiny bubbles of digestive gas that can cause bloating
• Probiotics to encourage the bacteria that help with digestion

If your bloating does not improve after trying home remedies, your GP or consultant may prescribe medication to treat the underlying condition. 

If you have ascites, this may include diuretics to help your kidneys remove the excess fluid that is causing your abdomen to swell or a procedure to physically remove the excess fluid. As ascites often occurs due to another serious health condition, such as liver cirrhosis, your doctor will discuss a treatment plan with you. 

If your stomach bloating is caused by IBS or lactose intolerance, there are not usually any medications that can help — reducing stress levels and avoiding trigger foods are the main forms of treatment. 

Other medications your doctor may prescribe for stomach bloating caused by gas include: 

• Charcoal preparations to absorb gas
• Medications to relieve muscle spasms to reduce bloating and distension — some of these medications are available without a prescription, such as mebeverine and alverine
• Simeticone to break up gas bubbles