A functional bowel disorder occurs if this normal function of the gut is not working correctly.  For example, if the muscle propels bowel contents too fast the patient gets diarrhoea, if it works too slowly constipation occurs.  If the muscle goes into spasm it can cause pain rather like muscular leg cramps.

3.       How do functional bowel disorders differ from other bowel diseases?

With functional bowel disorders the bowels look normal - it's the way they work which is disordered.  With other bowel diseases there is usually something abnormal to see - an ulcer, for example.  These are termed 'organic bowel disorders'.

4.       Does 'functional' mean it's all in the mind?

No, but many bowel symptoms are made worse by stress - this is true of both functional and organic bowel disorders.  Some people only get symptoms when they are under stress.  On the other hand, others are psychologically well adjusted and have no stress in their lives but can be plagued by functional bowel disorders.

5.       Is it the same as 'colitis'?

Although once called mucus or membranous colitis, this disorder is quite different from ulcerative colitis.  In the irritable bowel syndrome, muscle spasm seems to be the main problem, while in ulcerative colitis there is inflammation of the large bowel mucosa (lining).

6.       How common is it and who is affected?

IBS is extremely common in developed countries but may be less common in other countries, such as Africa and Asia.  Probably one third of the people in Britain have occasional symptoms and 1 in 10 have symptoms bad enough to require medical attention.  It commonly starts between 15 and 40 years of age and is more common in women.  However, it may affect any age.

7.       What are the main symptoms?

These may vary from patient to patient, but all will have at least some of the following:

•  Abdominal pain.  Most often it is colicky (gripey) in nature.  It may be felt anywhere in the abdomen, but often low down on the left.
• The pain is often relieved by passing flatus (wind from the back passage) or by bowel actions.
• A bloated and windy feeling.  Sometimes there are rumbling noises.
• Irregular bowels varying between diarrhoea, particularly around breakfast time, and constipation.  Many patients find their pain is worse when constipated.
• Small, hard, pelletty stools which may be covered in mucus.  It is also quite common to pass mucus alone.

8.       What other symptoms may occur?

• Urgency - a need to rush to open the bowels.  This can lead to incontinence if a toilet is not nearby.
• A feeling of incomplete emptying of the bowels after having them open.
• Tenderness in the abdomen.
• A brief, sharp spasm of pain felt low down inside the back passage (rectum) - "proctalgia fugax"
• Nausea, especially in the morning, belching, and occasionally vomiting.

9.       Are other organs affected?

Some patients with IBS may also have an irritable bladder causing frequency of passing urine, others may have indigestion and some women may find intercourse painful.

10.     What is the cause of this disorder?

IBS is an exaggerated response by the bowels to situations of tension associated with normal daily living, leading to abnormal contractions or movement and spasm of the bowel.  It is particularly likely to occur in an individual who eats an irregular diet, or one which is deficient in dietary fibre (roughage).  The breakfast meal is particularly important in this respect: an input of roughage first thing in the morning before the stresses and tensions of daily living start seems to 'kick start' and regulate bowel movements.

IBS sometimes follows an attack of viral or bacterial gastroenteritis/diarrhoea, particularly in a susceptible individual whose diet lacks dietary fibre..

There is no evidence that IBS is a bowel inflammation (like ulcerative colitis or Crohn's disease), hereditary (although other members of the family may also suffer from it), or a food allergy (although some patients find they are intolerant of particular foods, like wheat or milk).

11.     How do symptoms develop?

In general, muscle changes cause many of the symptoms.  For example:

•  Cramp-like pain or colic (muscle spasm)
• Diarrhoea (increased movement of bowel contents)
• Constipation (reduced movement of bowel contents).

12.     Are any investigations necessary?

Investigations are usually arranged to exclude other bowel disorders that produce the same symptoms as the irritable bowel syndrome.  In many young patients, the doctor may diagnose and treat the disorder without investigation.  In older patients, the doctor may do investigations to exclude other possible bowel disorders.  Some doctors may only investigate those who do not respond to a trial of treatment.  If some of the symptoms are not typical, such as weight loss or blood in the motions, investigations are necessary.

13.     What investigations are helpful?

• sigmoidoscopy - passage of a small tube through the anus to inspect the bowel
• blood tests, looking for anaemia or malabsorption
• examination of the stool for bleeding
• Barium Enema X-rays - the bowel looks normal in IBS although spasm is sometimes seen.
• Colonoscopy

14.     What treatment is available?

Although the irritable bowel syndrome may produce troublesome symptoms, it does not lead to serious complications.  Treatment consists of:

i) an explanation of the disorder and how symptoms are produced helps to relieve anxiety and allow the patient to cope with infrequent episodes of symptoms, and reassurance that more serious disorders are not present.

ii) increasing the fibre content of the diet particularly at breakfast time, encouraging the intake of foods such as high fibre breakfast cereals (e.g.. Weetabix, Shredded Wheat etc.), whole wheat bread, fruit, vegetable and berries, instead of refined foods such as white bread and desserts - see section 16 for a dietician's advice.

Sometimes it may be necessary or convenient to take fibre supplements in addition, although raw bran generally tends to make diarrhoea and wind/bloating worse.  In this situation it is usually better to take such medications as Fybogel or Regulan.

Severe spasm or colic pains may respond to an antispasmodic although in general, drug treatment should be avoided.

Diarrhoea may sometimes need treatment with drugs such as Loperamide (Imodium) especially at socially inconvenient times.

15      Can IBS be cured?

Having made the necessary adjustments to diet and lifestyle, there is a good chance that the symptoms will gradually subside and become bearable over the course of several weeks or months.  The IBS may well recur from time to time, particularly at times of stress or following a bout of diarrhoea, for instance due to food poisoning.

16      Dietician's advice

Increasing Fibre     Dietary  fibre helps to regulate bowel function and can ease both  constipation and  diarrhoea.  It is found in many different foods,  mainly cereal  products, vegetables and fruit.  Increase the amount gradually and always take plenty of fluids throughout the day to achieve the best results.

• Use wholemeal bread in preference to white or brown bread. There are many different types and brands to choose from.
• Choose cereals high in soluble fibre, e.g.. Weetabix, Shredded Wheat, Porridge Oats. These are higher than Cornflakes and Crisped Rice types. 
• Wholemeal flour can replace white flour in cooking. Try half of each to begin with. 
• There are many choices of high fibre biscuits now. Digestives, Oat Biscuits, Ryvita, Bran biscuits and whole-wheat crackers are better choices than arrowroot biscuits, shortcake and custard creams.
• Replace white pasta and rice with wholemeal pasta and brown rice.
• Use "pulse" vegetables: lentils and beans in soups, casseroles and on toast. These can replace some of the meat, fish, cheese and eggs in your diet, as they are also rich in protein. 
• All vegetables contain fibre so try to include at least 2 servings each meal. Always eat the skins where appropriate, e.g.. jacket potatoes. 
• Eat plenty of fruit, 2 or 3 pieces daily at least, preferably without peeling them first (except citrus fruits!). Dried fruit can be used to sweeten cereal or puddings in place of sugar and is useful as in snack food. 

• Avoid fried foods: grill, bake, boil, steam or microwave without adding fat. 
• Choose lean meats and extend casseroles with vegetables and pulses. Chicken and fish can be used more often. 
• Try low fat dairy products such as semi skimmed or skimmed milk, low fat yoghurts and fromage frais and lower fat cheeses. 
• Beware of "hidden" fats in cakes, pastries, chocolates and other food products. 
• Look out for other lower fat products: low fat spreads, crisps, sausages, etc. to replace the normal versions in the diet. 

Caffeine Intake      It is advisable to limit consumption of tea and coffee as caffeine can stimulate the bowel. 

Food Intolerances  Some people find that certain foods are associated with the symptoms of IBS.  If you suspect this, record which foods are concerned and discuss them with your doctor before eliminating them from your diet. Any food intolerance should be investigated properly with medical and dietetic care to avoid unnecessary restrictions and a diet that may be deficient. 

by        Dr P J Finch MD FRCP

            Consultant Gastroenterologist

and       Mrs E Hedges BSc SRD

            Dietetic Services Manager