The utility of diagnostic tests in irritable bowel syndrome patients: a systematic review

The aim of this study was to determine the pretest probability of organic GI disease and the accuracy of diagnostic tests for organic GI disease in patients who meet symptom-based criteria for irritable bowel syndrome (IBS).After a comprehensive literature search for studies examining the accuracy of diagnostic tests for organic GI disease among patients who meet symptom-based criteria for IBS, two independent observers qualitatively assessed the methodology of selected studies and extracted data. Data on the pretest probability of organic GI disease in this population and the accuracy of currently recommended diagnostic tests were converted to descriptive tables.Among patients meeting symptom-based criteria for IBS, the pretest probability of inflammatory bowel disease, colorectal cancer, or infectious diarrhea is less than 1%. Currently recommended diagnostic tests rarely identify organic GI disease in patients fulfilling symptom-based criteria for IBS. However, the pretest probability of celiac disease in patients meeting symptom-based criteria for IBS was 10 times higher than the prevalence of celiac disease in the general population.There is insufficient evidence to recommend the routine performance of a standardized battery of diagnostic tests in patients who meet symptom-based criteria for IBS. Based upon the increased pretest probability of celiac disease, routine performance of serological tests for celiac disease may be useful in this patient population, though additional study is needed in this area.