I just visited an experienced doctor and nutritionist recently who has cured IBS, and had a long discussion about IBS and the sole cause of IBS was diet and only diet. Basically, eating too much preservative foods, packaged foods and canned foods in North America induces too much chemicals into the digestive tract, which hinders the proper function of liver, small intestine, large intestine and colon. This temporary hampers the body's own function to heal itself by weakning the immune system. Hence to get back to the body's original state and reverse the process, the body needs to be kept from all these preserved and processed foods and also alcohol, caffeine, dairy products, fatty & fried foods for a long enough time for body's normal operation. Hence, avoidance of these foods for 1-2 months and keeping a diet which contains of homecooked meals, a lot of fresh fruits and cooked vegeatbles- specifically PAPAYA, NATURAL YOGURT are essential to the diet will return the body back to proper functional capability. But however, after healing, a long enough time span should be given before one can start introducing preservative foods occasionally (BUT ONLY in very minute quantities).