Bloating — when your lower tummy feels swollen and full — is very common. It is usually caused by something you’ve eaten and will go away by itself. But if you regularly feel bloated, there may be an underlying medical cause so you should see your doctor.

What is bloating?

Bloating is a feeling that your tummy is going to burst. You may also have cramps, burping, diarrhoea, constipation, swelling and a lot of gas.

It happens when the organs of your digestive system are stretched, for example when liquid, gas or solids pool in part of your gut. It can also happen when the contents of your stomach move too slowly through the digestive system; when you have weak muscles in the wall of your tummy; or when your diaphragm muscle contracts instead of relaxing.

What causes bloating?

Bloating is usually caused by changes in your diet, for example if you have eaten a lot of rich food. One theory is that what you eat changes the type of bacteria you have in your gut, leading to bloating and gas. 

Eating a lot of salty food and carbohydrates can make you feel bloated, as can swallowing air when you eat too fast or drink a lot of fizzy drinks.

Regular bloating can be caused by other problems, including:

• constipation 
• coeliac disease 
• food intolerance, usually to gluten, wheat or milk (lactose intolerance) 
• irritable bowel syndrome (IBS) 
• hormones, including before your period or during menopause 
• some medicines 
• gaining weight 
• stress 

Treating bloating

Bloating will usually go away by itself if you adjust your diet for a while. Cut down on salty foods, carbohydrates and fizzy drinks. For some people, it can help to avoid foods that contain onion or garlic, wheat, rye, lactose products or stone fruit.

Bloating caused by constipation can be treated by eating more high-fibre foods, increasing the amount that you drink, and exercising regularly. Some people may need laxatives to treat constipation. 

If you have a medical condition such as coeliac disease or IBS, you will need to follow a strict diet to prevent bloating and other symptoms. Studies have shown that following the low FODMAP diet can help with IBS. This involves cutting out some dairy products, wheat and other grains, and some fruits and vegetables. Talk to a health professional such as your doctor or a dietitian before starting this diet to make sure it is right for you.

If you have a food intolerance, you may need to try an elimination diet to find out which food or foods are causing your problems. Your doctor or dietitian will advise you. 

Some people find that probiotics containing lactobacillus and bifidobacterium can help with bloating by reducing the production of gas in the gut. 

How to prevent bloating 

To keep your digestive system working well, follow a healthy diet and eat at least 30g of fibre every day. Cut down on processed and fatty foods, and drink less alcohol. Drink plenty of water and take any medicines as directed by your doctor.

Don’t overeat, and try to eat more slowly. Eating regularly will help to prevent digestive problems.

Regular exercise is also important for your gut because it strengthens the muscles in your tummy and stimulates the digestive system to push food through. It also helps with stress, which affects the nerves in the digestive system and can slow down digestion.

Smoking is very bad for your digestion. If you smoke, try to quit now.

When to seek help for bloating

Rarely, bloating can signify that something more serious is wrong. If your bloating doesn’t get better by following the steps above, you should see your doctor. Seek medical attention if you have bloating as well as:

• diarrhoea
• persistent or severe abdominal pain
• blood in your stools (poo)
• changes in the colour or frequency of your stools
• weight loss without your trying to lose weight
• loss of appetite or feeling full quickly

If you’re unsure, healthdirect’s Symptom Checker can help you decide what to do next.