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

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

Flatulence is very common and it is something that everyone experiences regularly. Like breathing and sweating, flatulence is a normal biological process.  On average, people pass wind about 15 times a day, some people pass wind only a few times, others a lot more.

If you are suffering with flatulence you can use our online Flatulence Symptom Checker to find out what to do.

Why do we fart?

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 of excess gas and does so either by flatulence (farting) or belching (burping).

Sometimes, you may not notice you have passed wind because most of the gases are odourless and are often released in small quantities.

Flatulence usually only has a bad smell if it contains gases that smell, such as sulphur. However, it is important to remember that it is 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 is difficult to digest. Or it can be due to an underlying health problem that is affecting the digestive system.

There are also several medical conditions that can cause flatulence, such as constipation and irritable bowel syndrome (IBS), which is a condition that causes indigestion and bloating.

Read more about the causes of flatulence.

When to see your GP

There are no medical guidelines defining what the normal frequency or volume of flatulence is. You are therefore probably the best person to assess your own symptoms. You should see your GP if your flatulence is particularly troublesome, such as frequently passing smelly gas, for example.

You should visit your GP if you are experiencing other symptoms such as:

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


If you have excessive flatulence, the problem 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 the problem.

Read more about treating flatulence.

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Most cases of excessive flatulence are not serious and can be treated using self-care techniques. A visit to your GP is usually only recommended if you have additional symptoms that may suggest that you have an underlying digestive condition.

The symptoms of flatulence are usually only considered troublesome if:

  • you experience frequent episodes of flatulence
  • you pass an excessive amount of wind during an episode of flatulence
  • you consistently produce foul-smelling wind

There are no medical guidelines defining what is the normal frequency or volume of flatulence. Therefore, you are probably the best person to assess your symptoms. Treatment is available if you think that your symptoms have become troublesome.

Read more about treating flatulence.

When to seek medical advice

The additional symptoms listed below could be an indicator of a more serious health problem. You should visit your GP if you experience:

  • persistent abdominal pain and bloating
  • recurring episodes of diarrhoea or constipation
  • unexplained weight loss
  • bowel incontinence 
  • blood in your stools (faeces)
  • symptoms that may suggest that you have an infection, such as a high temperature, vomiting, chills, joint pain and muscle pain
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There are several natural causes of flatulence. Flatulence can also be caused by some health conditions that are related to the digestive system.

There are three main causes of excessive flatulence. They are:

  • swallowing more air than usual
  • eating food that is difficult to digest
  • having an underlying health condition that affects your digestive system

These are discussed below.

Swallowing air

It is perfectly normal to swallow air while breathing and eating.  However, it is easy to swallow a lot more air than usual without realising it.  This can lead to symptoms of excessive flatulence. Excess air can be swallowed by:

  • chewing gum
  • smoking
  • sucking on pen tops
  • not chewing food slowly and thoroughly (swallowing large pieces of food will result in you swallowing excess air)
  • having loose fitting dentures

Hot and fizzy drinks also increase the amount of carbon dioxide in your stomach, although this is more likely to lead to symptoms of belching rather than flatulence.

Food and drink

Much of the food that you eat is carbohydrate. Carbohydrates are made up of long chains of sugar molecules.  Some carbohydrates cannot be digested and absorbed by the intestines and pass down into your colon. These are known as unabsorbable carbohydrates, or fermentable oligo-, di- and monosaccharides and polyols (FODMAPs). 

Your colon contains more than 500 different types of bacteria. The bacteria start to break down the carbohydrates and, in the process, they produce gas, which is released as flatulence.

Foods that contain a high amount of unabsorbable carbohydrates include: beans, broccoli, cauliflower, cabbage, artichokes, raisins, pulses, lentils, onions, prunes, apples, brussel sprouts.

Slimming products that contain sorbitol (a sugar substitute) or fructose (a type of sugar) can also cause flatulence because both sorbitol and fructose are unabsorbable carbohydrates. Many fruit juices also contain high levels of fructose. 

Certain foods, such as cabbage or onions, can lead to the production of gases containing sulphur, which can result in foul smelling wind.

However, the production of smelly wind can vary from person to person depending on what you eat, so it is up to you to work out which foods cause the most smell.

Health conditions

Medical conditions that can cause symptoms of flatulence include:

  • constipation
  • irritable bowel syndrome (IBS) - a common digestive condition, which can cause stomach cramps, bloating, diarrhoea and constipation  
  • coeliac disease - an intolerance to a protein called gluten, found in wheat, rye and barley
  • lactose intolerance - which is where the body is unable to break down lactose (a natural sugar found in milk and dairy products) and cannot absorb it into the blood
  • gastroenteritis - which is a stomach and bowel infection
  • malabsorption, which is where the intestines are unable to absorb nutrients properly
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Flatulence does not usually require a medical diagnosis.  However, if you are also experiencing additional symptoms, such as persistent abdominal pain or blood in your stools you should see your GP.  These symptoms suggest that you may have an underlying digestive condition.

In these circumstances you will be given a blood test. This is used to check for the presence of infection. It can also determine whether you have a condition that is linked to a food intolerance, such as coeliac disease or lactose intolerance.

Your GP may also ask you about your symptoms and bowel movements, such as whether you have to strain to pass a stool or whether you experience abdominal pain after eating.   This type of information can be useful in confirming a diagnosis irritable bowel syndrome (IBS).

If you have additional symptoms that are particularly severe, your GP may refer you for an endoscopy. This is a procedure where a healthcare professional examines the inside of your stomach using a piece of equipment called an endoscope. An endoscope is a long, thin flexible tube that has a light and a video camera at one end.


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Excessive flatulence can usually be treated by making changes to your diet and lifestyle. There are also several over-the-counter treatments available if your flatulence is becoming a problem.

Self-care advice


Avoid eating foods that are high in unabsorbable carbohydrates (see causes of flatulence for a list).

However, it is still important for you to eat a healthy balanced diet, including at least five portions of fruit and vegetables a day. You should choose foods that contain carbohydrates that are easy to digest. These include:

  •  potatoes
  •  rice
  •  lettuce
  •  bananas
  •  grapes
  •  citrus fruits, such as oranges
  •  yogurt

It is important to note that different people will react differently to certain foods, so some of the foods listed above may still cause flatulence. It is therefore recommended that you keep a food diary to see whether certain foods make your symptoms better or worse.

You may find it useful to eat six small meals a day rather than three large ones. Smaller meals are easier to digest and may produce less gas. There is also some limited evidence to suggest that drinking peppermint tea can help improve the symptoms of flatulence.

Swallowing air

When eating, make sure that you chew your food slowly to reduce the amount of air that you are swallowing. This will also help with digestion.

Avoid chewing gum because it can also cause you to swallow more air than usual.

You should also give up smoking if you smoke. Smoking can cause you to swallow more air than usual and tobacco smoke can irritate your digestive system. 

Read more information and advice about how to give up smoking.


Taking plenty of exercise can help to improve the functioning of your digestive system and bowel. It has also been shown to help with bloating and the clearing of gas.

Medication and other remedies

There are several over-the-counter remedies that can be used to help treat the symptoms of flatulence.

Alpha-galactosidase is a dietary supplement that has been shown to improve the digestion of carbohydrates and reduce the symptoms of flatulence. It is found in a product called 'Beano', which has been shown to have some effect in reducing flatulence and is available from some pharmacists and health food shops.

Charcoal tablets are another type of medication that is available over the counter from pharmacists. The charcoal absorbs gas in the digestive system, which helps to reduce the symptoms of flatulence.

Charcoal tablets may not be suitable for you if you are currently taking other medication. This is because the charcoal might absorb the medication and make it less effective. If you are taking other medication, you should ask your GP or pharmacist for advice before taking charcoal tablets.

Clothing containing activated charcoal, or charcoal pads that are placed inside clothing, is intended to help absorb the gas that is released during flatulence. This can help mask foul-smelling gas.

Simethicone is another over-the-counter medication that can also sometimes help with gas problems

Probiotics may also be useful in treating flatulence. Probiotics are a dietary supplement, usually sold in liquid form, which encourage the growth of 'friendly bacteria' in your digestive system. The 'friendly bacteria' should help to aid digestion and reduce the symptoms of flatulence, particularly in those with irritable bowel syndrome (IBS).

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The information on this page has been adapted by NHS Wales from original content supplied by NHS Choices.
Last Updated: 31/10/2014 14:34:50

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