Irritable bowel syndrome or IBS refers to a condition associated with abdominal pain, bloating and erratic bowels with intermittent diarrhoea and constipation. It is a common disorder which is often worsened by stress and poor diet. Patients often need reassurance that more serious disorders are not present like colorectal cancer and inflammatory bowel disease.

The basis of IBS is probably a diffuse muscle disorder of the small and large bowel where there is variable intestinal muscle wall spasm and flaccidity. This is often unpredictable and can lead to troublesome diarrhoea, often with the passage of mucus and at other times marked constipation.

Medical treatment of IBS involves a thorough history and examination to understand the frequency and severity of symptoms and to exclude other conditions. A gastroscopy and colonoscopy is often performed to exclude other disorders like coeliac disease, inflammatory bowel disease or colorectal cancer. Sometimes, biopsies of the lining of the first part of the small bowel, the duodenum, are taken to exclude enzyme deficiencies. The lack of certain digestive enzymes may be associated with or even the under cause of irritable bowel syndrome.

For some patients the reassurance that their symptoms are not due to colon cancer or inflammatory bowel disease is of great comfort and the symptoms improve. Other patients improve with stress reduction and dietary changes. The low FODMAP diets can be very helpful in reducing exposure to the trigger foods which produce symptoms.

In very severe cases, probiotics are sometimes helpful and occasionally, when other measures fail, low dose anti-depressant medications are useful to reduce symptoms.