Flatulence - Causes 

Causes of flatulence 


Irritable bowel syndrome (IBS) is a common gut disorder that affects up to one in five people. Symptoms vary from abdominal pain and bloating to bouts of diarrhoea or constipation, but can often be eased with treatment.

Media last reviewed: 25/10/2013

Next review due: 20/10/2015

Eat right for your digestion

How to eat and drink to ensure a good digestion, including foods to avoid and which ones to fill up on.

There are several natural causes of flatulence. Flatulence can also be caused by some health conditions that are related to the digestive system.

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 cause excessive flatulence.

Excess air can be swallowed by:

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

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

Food and drink

Much of the food we 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 produce gas, which is released as flatulence.

Foods that contain a high amount of unabsorbable carbohydrates include:

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

Other foods and drinks containing a sweetener called sorbitol (such as sugar-free gum or slimming products), or a type of sugar called fructose (such as fruit juice), can also cause flatulence.

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

Health 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 – 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 – a stomach and bowel infection
  • malabsorption – where the intestines are unable to absorb nutrients properly

Page last reviewed: 25/04/2013

Next review due: 25/04/2015


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The 3 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Phartosis said on 18 August 2014

I have very bad flatulence though I have noticed from what's been written above that I can see a lot of the culprits right there. I eat far too fast, I wolf down my food. I also chew sugar-free gum which contains sorbitol. I eat lots of broccoli, cauliflower, Brussel sprouts, apples, beans and beans. As I'm a veggie I'm going to try and simply eat slower whilst cutting out the gum and see where that takes me. I also find that along with the farting I also suffer with an increased bowel urgency - when I need to go I have to go. I didn't experience any of this while a meat-eater so maybe it's the vegetarianism? I'll give this a go because I can't go on like this for too much longer. My farting is alienating house-mates and certainly not going any way towards me winning friends and influencing people.

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maysie said on 30 March 2013

Charcoal tablets will absorb the smell from the bowel from the inside , but a good strong probotic and digestive enzymes will help the digestive process significantly. Cut out sugar too . Chew food slowly aids digestion and drink very little with meals too.

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Concerned wife said on 09 March 2013

My husband has several serious medical conditions, severe heart failure, kidney failure, diabetes and is just generally in a bad way, although his strength has improved in recent months.
Most of his needs are met by the various consultants and our local surgery.
However, some years ago he suffered, and was operated on, for diverticulitis, resulting in the removal of part of his bowel. Recently he has been suffering from extremely pungent wind, which is so bad I can't stay in the same room.
He's always had a bit of a wind problem but its now becoming so bad that I am now trying to get other perspectives on it.
He was suspected of having bowel cancer at the end of 2012, but was unable to have it confirmed because the procedures involved would most likely have proven terminal in themselves.
His general health has improved after a long course of iron tablets but because of the dangers involved we still don't know what the situation is. But our concerns at this moment revolve around this horrendous flatulence. Can anyone help?

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