Irritable bowel syndrome (IBS) is the most common of all intestinal disorders. It affects 10-20 per cent of adults in parts of the developed world, and twice as many women as men suffer from the condition. IBS symptoms include alternating diarrhoea and constipation, cramping pains in the lower abdomen and production of copious amounts of flatulence. There are several causes of IBS. The basic one is disturbance in the function of the large intestinal muscle. This may be due to stress, fear or serious illness. IBS may also be due to an overgrowth of organisms, such as Candida albicans, in the digestive tract.