Irritable bowel syndrome: new and emerging therapies

Irritable bowel syndrome refers to abdominal discomfort associated with altered bowel habits. Recent evidence suggests that the primary pathophysiologic mechanism is brain-gut dysregulation. Many central and peripheral factors are involved. This article will review important pathophysiologic mechanisms with a focus on new and emerging therapies.

Prior gastroenteritis and small intestinal bacterial overgrowth may be important for treatment of irritable bowel syndrome. Understanding of serotonergic receptors in gastrointestinal function has led to the development of serotonergic agents such as alosetron and tegaserod. Novel agents targeting other receptor sites include neurokinin and neurohormonal modulators, chloride channels and opioid receptors. Other therapeutic approaches - behavioral treatments, probiotics, antibiotics and alternative therapies - have developing roles in the treatment of irritable bowel syndrome.

A better understanding of pathophysiologic mechanisms has resulted in therapeutic advances. Prokinetic therapies may have a role in nondiarrhea predominant irritable bowel syndrome. Antidepressants are used to modulate pain and treat comorbid psychological distress. Newer agents target various receptor sites. Advances in psychological/behavioral treatments and alternative modalities hold promise for the future.