Evidence- and consensus-based practice guidelines for the diagnosis of irritable bowel syndrome

Background: Irritable bowel syndrome (IBS) presents a significant diagnosti c and management challenge for primary care practitioners. Improving the ac curacy and timeliness of diagnosis may result in improved quality and effic iency of care. Objective: To systematically appraise the existing diagnostic criteria and combine the evidence with expert opinion to derive evidence- and consensus- based guidelines for a diagnostic approach to patients with suspected IBS. Methods: We performed a systematic literature review (January 1966-April 20 00) of computerized bibliographic databases. Articles meeting explicit incl usion criteria for diagnostic studies in IBS were subjected to critical app raisal, which formed the basis of guideline statements presented to an expe rt panel. To develop a diagnostic algorithm, an expert panel of specialists and primary care physicians was used to fill in gaps in the literature. Co nsensus was developed using a modified Delphi technique. Results: The systematic literature review identified only 13 published stud ies regarding the effectiveness of competing diagnostic approaches for IBS, the accuracy of diagnostic tests, and the internal validity of current dia gnostic symptom criteria. Few studies met accepted methodological criteria. While symptom criteria have been validated, the utility of endoscopic and other diagnostic interventions remains unknown. An analysis of the literatu re, combined with consensus from experienced clinicians, resulted in the de velopment of a diagnostic algorithm relevant to primary care that emphasize s a symptom-based diagnostic approach, refers patients with alarm symptoms to subspecialists, and reserves radiographic, endoscopic, and other tests f or referral cases. The resulting algorithm highlights the reliance on sympt om criteria and comprises a primary module, 3 submodules based on the predo minant symptom pattern (constipation, diarrhea, and pain) and severity leve l, and a subspecialist referral module. Conclusions: The dearth of available evidence highlights the need for more rigorous scientific validation to identify the most accurate methods of dia gnosing IBS. Until such time, the diagnostic algorithm presented herein cou ld inform decision making for a range of providers caring for primary care patients with abdominal discomfort or pain and altered bowel function sugge stive of IBS.