Diagnosis of irritable bowel syndrome.

Because there are no reliable biological or laboratory markers associated with the condition, the diagnosis of irritable bowel syndrome(IBS) is based on patient descriptions of common symptoms such as abdominal pain accompanied by changes in stool form or frequency and associated symptoms such as bloating and distension. With the development and refinement of symptom-based criteria for the diagnosis of IBS, the traditional need for a negative diagnostic evaluation has been questioned. This article evaluates the diagnostic characteristics of various symptom-based criteria in routine clinical practice and reviews the data regarding the yield of the multiple commonly used diagnostic tests in patients with suspected IBS.