When to reconsider the diagnosis of irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a highly prevalent disorder characterized by nonspecific symptoms that can mimic other common medical conditions. A careful history and physical examination may reveal clues that suggest a coexisting or alternative diagnosis, such as small intestinal bacterial overgrowth or celiac disease (CD). Testing for bacterial overgrowth has limitations, but emerging data suggest that antibiotics may be of some benefit in patients with IBS with diarrhea and bloating. CD seems to have a higher prevalence in patients with IBS. Some patients with IBS may have symptomatic improvement on gluten-restricted diets, without histologic or serologic evidence of CD.