Rifaximin Therapy for Patients with Irritable Bowel Syndrome without Constipation

In two trials involving patients with irritable bowel syndrome without constipation, 2 weeks of treatment with the minimally absorbed antibiotic rifaximin was more effective than placebo in providing adequate relief of symptoms. The irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by recurring symptoms of abdominal pain, bloating, and altered bowel function in the absence of structural, inflammatory, or biochemical abnormalities. 1 IBS often does not respond to current treatment options, including dietary and lifestyle modifications, fiber supplementation, psychological therapy, and pharmacotherapy. 2 , 3 Because no reliable biologic or structural markers have been identified, the effects of pharmacotherapy are typically assessed by asking patients to report whether they had adequate relief of IBS symptoms (with a binary response of yes or no). 4 Given the limitations of available therapies, there is an unmet . . .