[Diagnosis of irritable bowel syndrome].
According to Rome II criteria, irritable bowel syndrome is defined as a group of functional bowel disorders in which abdominal discomfort or pain is associated with defecation or change in bowel habit and is associated with features of disordered defecation. A diagnosis is based on identifying the consistent symptoms with the exclusion of other organic or functional disorders having similar clinical presentations in a cost-effective manner. A physical examination should be performed on the first visit and on subsequent visits as needed. Two algorithms for the evaluation of patients seen in primary care settings and two other algorithms for patients presenting to gastroenterologists are presented. In general, if Rome II criteria are fulfilled, alarm features are not present, and screening studies from the referring physician are negative, further testing is not needed. Screening studies are recommended when certain historical information is present. In many cases, the therapeutic trial can be undertaken before further diagnostic studies are done and will depend on the symptom subtype and its severity. It needs to be emphasized that patients presenting with typical symptoms and no alarm signs are rarely found to have another diagnosis, supporting the benefit of ongoing care and symptomatic management rather than continued diagnostic evaluation. If initial treatment fails, or certain clinical features emerge requiring further evaluation, studies may be performed by gastroenterologists in specialty centers.