Flatulence is passing gas from the digestive system out of the back passage. It's more commonly known as "passing wind", or "farting".

Farting is often laughed about, but excessive flatulence can be embarrassing and make you feel uncomfortable around others. However, it can usually be controlled with changes to your diet and lifestyle.

Flatulence is a normal biological process and is something everyone experiences regularly. Some people pass wind only a few times a day, others a lot more, but the average is said to be about 5 to 15 times a day.

Why it happens

When you swallow food, water or saliva, you also swallow small amounts of air, which collects in the digestive system. Gases can also build up when you digest food. The body needs to get rid of the build-up by farting (flatulence) or burping (belching).

Sometimes you may not notice you have passed wind because most of the gases are odourless and often released in small quantities. Flatulence usually only has a bad smell if it contains gases that smell, such as sulphur. However, it's important to remember it's normal for the gas you pass to sometimes smell a bit.

Excessive flatulence can be caused by swallowing more air than usual or eating food that's difficult to digest. It can also be related to an underlying health problem affecting the digestive system, such as recurring indigestion or irritable bowel syndrome (IBS).

Read more about the causes of flatulence.

When to see your GP

There are no medical guidelines defining the normal frequency or volume of flatulence. You're probably the best person to assess your own symptoms.

See your GP if your flatulence is particularly troublesome – for example, if you're frequently passing smelly gas.

You should also visit your GP if you experience additional symptoms, such as:

These symptoms could be an indicator of a more serious health problem and may require investigation, such as a blood or stool test to look for an infection.

Controlling the problem

Excessive flatulence can usually be controlled by making changes to your diet and lifestyle, such as:

  • avoiding foods known to cause flatulence
  • eating smaller and more frequent meals
  • eating and drinking slowly
  • exercising regularly

There are also some over-the-counter medications that can help if your flatulence is troublesome, such as charcoal tablets or simethicone.

If your flatulence is related to an underlying health problem, treating the condition may help resolve it.

Read more about treating flatulence.

Page last reviewed: 20/03/2015

Next review due: 20/03/2017