Dietary fiber and other alternative therapies and irritable bowel syndrome

Dietary fiber has demonstrated benefits in health maintenance, disease prevention, and in medical nutrition therapy. Dietary fiber is consumed in foods, dietary supplements, and in over-the-counter drugs as an aid to laxation. In developed countries, usual intake of dietary fiber is only about half of recommended levels. Irritable bowel syndrome (IBS) is the world's most common gastrointestinal functional disorder and greatly limits patients' quality of life. The pathological mechanisms of IBS are unknown, but consumption of dietary fiber may have therapeutic benefits for patients with the syndrome. Some studies find that soluble fibers are more successful than insoluble fibers in the management of IBS. Other fibers shown to have a positive effect on irritable bowel symptoms include wheat dextrin, partially hydrolyzed guar gum, and psyllium. Little data are available on probiotics and prebiotics and IBS. Other alternative therapies including peppermint oil, zinc, arginine, and restricted fructose intakes have been promoted for IBS. Dietary management of IBS must be individualized as symptoms of IBS vary widely.