Flatulence

Page last reviewed: 13/07/2011

Flatulence is the medical term for passing gas from the digestive system and out of the anus (back passage). It is more commonly known as "passing wind" or farting.

Gas can collect in the digestive system in two ways:

  • When a person swallows food, water or saliva they also swallow a small amount of air, which is mostly made up of oxygen and nitrogen.
  • When a person digests food, gas is released during the digestive process, mostly in the form of hydrogen, methane and carbon dioxide.

The body needs to get rid of the build-up of excess gas and does so in two ways:

  • flatulence (farting)
  • belching (burping)

How common is flatulence?

Flatulence is very common and everyone experiences it. It is a normal biological process, just like breathing or sweating. Most men will pass wind between 14-25 times a day and most women between 7-12 times a day.

Sometimes, you may not notice that you have passed wind because the gases that are passed are usually odourless and are often released in small quantities. The bad smell commonly associated with flatulence is caused by trace elements of sulphur gases, which can develop if food has not been properly digested and begins to decompose.

Outlook

If you have excessive flatulence, the problem can usually be controlled by making changes to your diet and lifestyle.

There are a number of medical conditions that can cause symptoms of flatulence, such as constipation and irritable bowel syndrome (IBS). IBS is a common but poorly understood condition that causes symptoms of indigestion and bloating. 

In these circumstances, medication may be required to help control the symptoms of flatulence while also treating the underlying health condition.


Anus
The anus is the opening at the end of the digestive system where solid waste leaves the body.
 Bacteria
Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and some others are good for you.
 Gut
The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.
 Lungs
Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.
 Oxygen

Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.

Stomach
The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.

Page last reviewed: 13/07/2011

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 the normal frequency or volume of flatulence is. Therefore, you are probably the best person to assess your symptoms. If you think that your symptoms have become troublesome, seek treatment for them.

When to seek medical advice

Most cases of excessive flatulence are not serious and can be treated using some 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. These symptoms include:

  • persistent abdominal pain and bloating
  • recurring episodes of diarrhoea or constipation
  • unexplained weight loss
  • bowel incontinence
  • blood in your stools (faeces)

Also look out for any symptoms that suggest that you have an infection, such as a high temperature, vomiting, chills, and joint and muscle pain.

Anxiety
Anxiety is an unpleasant feeling when you feel worried, uneasy or distressed about something that may or may not be about to happen.
Stomach
The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.

Page last reviewed: 13/07/2011

There are three main causes of excessive flatulence:

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

Swallowing air

While it is perfectly normal to swallow air during breathing and eating, it is easy to swallow a lot more air than usual without realising it. This can lead to symptoms of excessive flatulence.

Ways that an excess amount of air can be swallowed include:

  • chewing gum
  • smoking
  • sucking on pen tops
  • not chewing food slowly and thoroughly (swallowing large lumps of food will result in you swallowing more air)

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

Food

Much of the food that you eat is carbohydrates, which are made up of long chains of sugar molecules.

Some carbohydrates cannot be digested and absorbed in the intestines, and pass down into your colon.

These types of carbohydrates are known as unabsorbable carbohydrates. 

Your colon is home to more than 500 different types of bacteria. The bacteria begin to break down the carbohydrates and, in the process, produce gas that is released as flatulence.

Foods that contain a high amount of unabsorbable carbohydrates include:

  • beans
  • broccoli
  • cabbage
  • cauliflower
  • artichokes
  • raisins
  • pulses
  • lentils
  • prunes
  • apples
  • Brussel sprouts

Slimming products that contain the sugar substitute sorbitol, 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.

As many of the foods that contain unabsorbable carbohydrates are digested over a longer period of time, any undigested food can eventually begin to decompose. This releases a small amount of sulphur gas which causes the foul smell that is associated with flatulence.

Health conditions

Health conditions that can cause symptoms of flatulence include:

  • constipation
  • irritable bowel syndrome (IBS)
  • coeliac disease - a condition that is caused by a food intolerance to a protein called gluten and is found in wheat, rye, and barley
  • lactose intolerance - lactose is a natural sugar that is found in milk
Antibiotics
Antibiotics are medicines that can be used to treat infections caused by micro-organisms, usually bacteria or fungi. For example amoxicillin, streptomycin and erythromycin.
Anus
The anus is the opening at the end of the digestive system where solid waste leaves the body.
Bacteria
Bacteria are tiny, single-celled organisms that live in the body. Some can cause illness and disease and some others are good for you.
Constipation
Constipation is when you pass stools less often than usual, or when you are having difficulty going to the toilet because your stools are hard and small.
Enzymes
Enzymes are proteins that speed-up and control chemical reactions, such as digestion, in the body.
Kidney
Kidneys are a pair of bean-shaped organs located at the back of the abdomen, which remove waste and extra fluid from the blood and pass them out of the body as urine.
Stomach
The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.
Thyroid
The thyroid is a jointed piece or cartilage that enclosed the vocal cords and forms the Adam's apple in men.  

Page last reviewed: 13/07/2011

Flatulence does not usually require a medical diagnosis unless you are also experiencing additional symptoms, such as persistent abdominal pain or blood in your stools, which may suggest that you have an underlying digestive condition.

In these circumstances, a blood test can be used to check for the presence of infection and to 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 detailed questions about your symptoms and your bowel movements, such as whether you have to strain to pass a stool or if you experience abdominal pain after eating. This sort of information can be useful in confirming a diagnosis of irritable bowel syndrome (IBS).

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

Blood
Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Constipation
Constipation is when you pass stools less often than usual, or when you are having difficulty going to the toilet because your stools are hard and small.
Pain
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
Stools
Stool (also known as faeces) is the solid waste matter that is passed from the body as a bowel movement.

Page last reviewed: 13/07/2011

Self-care advice

Excessive flatulence can usually be treated by making changes to your diet and lifestyle. Avoid eating foods that are high in unabsorbable carbohydrates (see Flatulence - Causes for a list).

It is still important for you to eat a healthy, balanced diet that includes at least five portions of fruit and vegetables a day. You should choose foods that contain carbohydrates that are easy to digest. For example:

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

However, it is important to note that different people will react differently to certain foods, so some of the foods listed above may still cause you flatulence. Therefore, it is 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 should produce less gas.

Make sure that you chew your food slowly and thoroughly in order to reduce the amount of air that you are swallowing.

Taking plenty of exercise can help to improve the functioning of your digestive system and bowel, and reduce symptoms of gas.

There is some limited evidence that drinking peppermint tea can help improve the symptoms of flatulence.

If you smoke you should quit. Smoking causes you to swallow more air than normal, and tobacco smoke can irritate your digestive system.

Chewing gum should also be avoided because this also causes you to swallow more air.

Over-the-counter remedies

An over-the-counter (OTC) medication for flatulence is charcoal tablets. The charcoal absorbs gas in the digestive system, which should help to reduce the symptoms of flatulence.

Charcoal tablets may not be suitable for you if you are currently taking other medication because the charcoal could absorb the medication, making it less effective. If you are taking other medication, ask your GP or pharmacist, for advice before taking charcoal tablets.

Charcoal pads are also available. These are pads that you place in your underwear which help absorb the gas that is released during flatulence. Charcoal pads may also help to mask the smell of foul-smelling gas.

Probiotics may also be useful in treating of 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 symptoms of flatulence.

Diarrhoea
Diarrhoea is the passing of frequent watery stools when you go to the toilet.
Gut
The sac-like organ of the digestive system. It helps digest food by churning it and mixing it with acids to break it down into smaller pieces.
Pain
Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
Vomiting
Vomiting is when you bring up the contents of your stomach through your mouth.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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