What is Irritable Bowel Syndrome?

This article discusses the common condition of Irritable Bowel Syndrome (IBS) and outlines steps we can all take to prevent IBS and its related symptoms of constipation, diarrhoea and abdominal pain.


What is Irritable Bowel Syndrome (IBS)?

An extremely common bowel condition that leads to symptoms such as diarrhoea or constipation. Investigations (such as endoscopy) do not show any structural abnormality of the bowel.

What are the typical symptoms of IBS?

Diarrhoea – urgency (having to rush to loo), frequent and loose stools that may be painful. Often having to go to the toilet soon after eating.
Constipation – nothing for days/passage of pellets. Often having to return to the loo shortly after going to pass another pellet.
Abdominal pain

Why do people suffer with IBS?

The gut is a long pipe surrounded by muscle and filled with nerve endings. Normal muscle contractions (peristalsis) propel food/fluid and faeces in a coordinated manner down the entire length of our gut. In IBS weak contractions mean that the food and stool isn’t propelled down efficiently, leading to constipation. Conversely, over-active contractions can lead to diarrhoea. The gut is normally collapsed but can become distended with air resulting in bloating. The nerve endings in the gut wall may become more sensitive to stretching resulting in pain.

Who gets IBS?

  • IBS can run in families and is more common in women.
  • A previous episode of food poisoning can make people prone to this condition.
  • Previous antibiotic use/anti-inflammatory use (NSAIDs) may lead to IBS.
  • It may be related to a previous physical or emotional illness.
  • Stress/anxiety can affect gut contractions.

Treating symptoms


Are you:

1. A fast eater? (air swallower)
2. A gum chewer? (this leads to swallowing of air with saliva)
3. A lover of fizzy drinks? (this can fill you full of gas)
4. Eating too much fibre?

If the answer is yes to any of these – cut back!

Fibre is a carbohydrate present in fruit and vegetables. Fibre is not absorbed into the body by the gut but enters the bowel where our natural bacteria break it down into gas that causes symptoms of wind. Cutting back on wholemeal bread, fruit and fibre cereals and also cutting back on onions, mushrooms, leafy green vegetables and pulses (peas and beans) can have a dramatic effect on symptoms. Fatty meals tend to slow down the emptying of food from the stomach and this can also cause bloating, so rich meals are best avoided.


I suggest you look at your intake of the following and cut back:

1. Too much coffee/caffeine? These are gut stimulants and must be cut back.
2. Do you chew low sugar gum? This contains sorbitol and is a laxative.
3. Do you drink above the recommended limits of alcohol? Alcohol can cause diarrhoea.
4. Too much dairy such as cheese/cream/chocolates? This can cause diarrhoea.
5. Too many vegetables especially beans/cabbage/mushrooms/onions? Cut back.
6. Too much anxiety? This is difficult to treat, but try living life more slowly.

Further treatment of diarrhoea

Cut back on the foods above.

  • Increasing consumption of white rice may help (through mopping up water in the gut in the same way it absorbs water when cooked).
  • Avoid anti-inflammatories (aspirin and similar pain killers) and antibiotics.
  • Consider using small doses of loperamide (immodium) available over the counter to reduce bowel frequency.
  • Relaxation therapy/meditation/hypnosis may help you relax.

Abdominal pain

The pain of IBS is usually due to increased gut contractions. Treating the diarrhoea or constipation first is often the way forward. If this fails then you could try anti-spasm medication such as

  • Merbentyl/mebeverine before meals
  • Buscopan for attacks of pain
  • Amitriptyline low dose at night
  • Hypnotherapy


Things to think about:

  • Are you in a dehydrating environment? A warm environment will cause more water to be absorbed from your colon and hence your stool will become harder.
  • Are you drinking enough fluid? At least two litres of plain water per day should be drunk.
  • Are you drinking too much caffeine (diuretic)? This will cause you to pass more urine and become dehydrated.
  • Are you exercising? Exercise sends signals to the gut to keep it contracting and helps with regular bowel actions.
  • Are you eating enough fibre in your diet? Fibre in the form of wholemeal foods and nuts, peas and beans acts as a good laxative but be careful because too much causes bloating (see above).
  • Eating regularly? Eating regular meals sends signals from the stomach to the bowel to keep it contracting and helps with regular bowel actions.
  • Do you deny yourself? Sometimes you get the signal to open your bowels but don’t like the look of the toilet and as human beings we can resist the urge to go. The problem is that for people with sluggish bowels you might not get another signal for hours or even days.
  • Are you bearing down properly? When expelling stool, breathe in and blow your tummy out (make it fat). This should help you relax your pelvic floor muscles and allows you to bear down with pressure. Also try placing your feet on a small step 15–20cm high, this again helps to relax the pelvis.

Treating constipation

1. Drink at least two litres of water daily.
2. Eat regular meals, especially breakfast.
3. Avoid coffee.
4. Exercise regularly.
5. Eat fibre but don’t overdo it!
6. Avoid too much white rice which can be constipating.
7. Don’t ignore mother nature and go when you have the urge!

If you need help then a laxative is the answer. This may be in the following forms available from chemists:

1. A suppository (a small tablet placed into the bottom).
2. An enema (liquid inserted up the bottom).
3. Senna – tablets that help the gut to contract. These should not be taken long term.
4. A stool softener such as Milpar to help expel the stool.
5. A more effective laxative is a macrogol such as Movicol that comes in sachet form. This laxative does not get absorbed but instead works within the gut to help produce a soft, easy to expel stool. The precise dose you need varies between individuals.

When is IBS not IBS?

  • If you have blood/pus in your stool.
  • If you are getting up at night with diarrhoea.
  • If you have a change in bowel habit and are over 45.
  • If you have a change in your “normal” IBS symptoms.

Then you should discuss these symptoms with your GP for possible referral.

What might happen if you meet me?

1. We will discuss your symptoms and focus on diet in particular.
2. We will agree a treatment strategy.
3. If your symptoms are new/changing I might consider blood tests to check for blood count, protein level and markers of inflammation. A wheat allergy test might also be taken.
4. If your symptoms warrant it then perhaps a colonoscopy (bowel examination) will be required.


IBS symptoms can be troublesome but are treatable and with the correct review of your diet it should be possible to help your symptoms get better.

Further sources of information

Hertfordshire Gastroenterology

British Society of Gastroenterology

CORE – Charity supporting research into gut and liver disease

For further information on the author of this article, Consultant Gastroenterologist, Dr Simon Greenfield, please click here.
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