IRRITABLE BOWEL SYNDROME  - Full extract 

Irritable Bowel Syndrome (IBS) is one of the commonest conditions we see in General Practice. For many people it is quite literally a pain in the gut. 

The bowel can be regarded as a long hollow tube. It has a special lining through which food is absorbed, and a layer of muscle in its wall. Spasms of abdominal pain may occur if this muscle layer contracts too tightly. However, this only partly explains just one of the symptoms of IBS. 

In some ways IBS is a diagnosis of exclusion, what we are left with after ruling out other conditions. It has had a variety of names like spastic colon, irritable colon, nervous diarrhoea, spastic colitis, and functional diarrhoea. When there are so many names for a medical condition it usually means we do not know much about it. IBS is no exception. 

IBS is twice as common in women and it usually appears for the first time in young adults. 

A wide range of symptoms can occur, the most common being abdominal pain. This may be relieved by a bowel movement or passing wind. There is often a distended, bloated feeling in the abdomen, as well as a sensation that the bowel has not emptied properly. Both constipation and diarrhoea can occur, the stools varying from being mucousy and loose, to at other times being like hard pellets. There may be associated indigestion and nausea, as well as general symptoms like lack of energy. 

The precise cause of IBS is not clear. Normally, rhythmic contractions of the muscle layer in the bowel wall causes a smooth wave-like movement of bowel contents along its length. Somehow this smooth movement does not occur with IBS. A number of separate factors may be responsible. Stress and anxiety seem to play a major role in some people but are not the full explanation. Lack of dietary fibre can be a factor, as may intolerance or sensitivity to certain food substances. Rather persistent IBS symptoms have also been seen to follow infections like gastroenteritis. 

It is likely that several factors, either independently or collectively, cause symptoms in someone who is susceptible. Despite the annoying discomfort of IBS, there are no serious complications from the condition. The bowel is not going to twist, block or perforate and there is no association at all with conditions like cancer of the bowel. 

However, it is important to be on the alert for conditions like cancer of the bowel because the initial presentation can be quite similar. 

If there is any doubt about the diagnosis, a thorough investigation is necessary to rule out a more serious cause. Tests like a colonoscopy may be arranged so that the full length of the large bowel can be directly visualized. With this test a specialist passes a flexible narrow tube with a light on the end through the anus and around the bowel to the appendix area. It will rule out problems like benign polyps and bowel cancer, as well as conditions such as ulcerative colitis, where the lining of the bowel has become very inflamed. In some cases a more limited bowel inspection called a sigmoidoscopy may be performed. 

All these tests are more likely to be suggested in patients over the age of 40 years, and especially if there is a family history of bowel cancer. However, bleeding from the bowel is a particular symptom that always requires full investigation. 

For patients with the typical symptoms of IBS, a full history and examination by the treating doctor may be all that is required. For a diagnosis of IBS to be made, the physical examination and any investigations must be normal. Despite extensive research, no specific underlying bowel abnormality has yet been found with IBS. 

The treatment of IBS should begin with a careful assessment of lifestyle factors. A clear explanation and reassurance that there is nothing sinister going on is very important. Every effort should be made to reduce stress where possible; relaxation therapy may be helpful for some patients. 

A balanced diet with adequate fruit, vegetables and natural fibre is recommended. This is of application in patients where constipation has been a problem. Any foods which seem to trigger off IBS symptoms should be avoided. And the short term use of either antispasmodic drugs or peppermint oil capsules may also give relief. 

IBS is a condition that tends to recur at intervals. However, most patients learn to control their symptoms very well. 

Health tips:
 * Any change in bowel habit should always be checked with your doctor. Bleeding from the bowel is a symptom that should always be fully investigated.

* There is a great variability in the pattern of symptoms of Irritable Bowel Syndrome. Take a careful look at the specific things that seem to aggravate your symptoms, and then discuss them with your doctor.

* Increasing natural fibre and bulk in the diet is most useful when there has been a tendency to constipation.

Dr. Andrew Pattison: Common Consultations
North East Valley Division General Practice, Melbourne, Australia.   Disclaimer
  - Last modified: August 18, 2001