Irritable bowel syndrome (IBS) is a syndrome, a pattern of symptoms such as pain and bloating, of which the underlying cause is abnormal contraction of the intestinal muscles. People with IBS may experience constipation, diarrhoea, or a combination - constipation at some times and diarrhoea at other times. In addition, IBS may produce cramps, urgency or a gassy, bloated feeling in the abdomen. Mucous, sometimes seen in bowel movements, is also a symptom of IBS.
Diagnosis is hard because IBS can have mild or severe symptoms. IBS comes and goes during a patient's lifetime. Moreover, early IBS symptoms and inflammatory bowel disease symptoms are similar, namely pain, constipation and diarrhoea.
The proposed causes of IBS are stress, anxiety and a poor diet. The intestine in IBS sufferers contracts more vigorously after eating, which anti-spasmodic drugs can counteract. Other approaches are a no-milk high-fibre diet and painkillers.
Up to 20% of the British population is affected by IBS. It affects more women than men.