Psychotherapeutics and serotonin agonists and antagonists.

Treatment of irritable bowel syndrome (IBS) remains challenging for patients and practitioners. Current therapeutic choices include antidepressants and psychotherapy, which are thought to target central nervous system triggers of symptoms. Data supporting these treatments are reviewed. Therapeutic agents targeted at receptors in the enteric nervous system have recently been developed to act locally in the gut. Alosetron, an antagonist for serotonin-3 receptors, reduces intestinal motility, secretion, and possibly sensitivity. It is effective for diarrhea predominant IBS, although there are some potentially serious side effects. Tegaserod, a serotonin-4 receptor agonist, is a prokinetic agent that speeds small bowel transit and right colon transit in IBS, reducing symptoms of constipation, pain, and bloating. IBS symptoms are improved with integration of old and new therapies, combined with reassurance, education, and lifestyle adjustments.