J Clin Gastroenterol 2002 Mar;34(3):221-4 Increased prevalence of irritable bowel syndrome in patients with gastroesophageal reflux.Pimentel M, Rossi F, Chow EJ, Ofman J, Fullerton S, Hassard P, Lin HC.GI Motility Program, Department of Medicine, Cedars-Sinai Medical Center, CSMC Burns & Allen Research Institute, Los Angeles, California; and the School of Medicine, University of California, Los Angeles, Los Angeles, California, U.S.A.GOALS: To determine the prevalence of irritable bowel syndrome -IBS- in subjects with gastroesophageal reflux disease GERD compared with non-GERD controls. STUDY: Two hundred subjects were identified from a list of Cedars-Sinai Medical Foundation patients and gastroenterology motility practice subjects with and without a potential diagnosis of GERD. All subjects were then evaluated independently by two blinded physicians who were asked to identify subjects with GERD based on taking a history: gold standard. A follow-up questionnaire was later mailed to patients. This questionnaire included Rome I criteria for IBS. The prevalence of IBS was compared between GERD and non-GERD subjects. Finally, to further strengthen the method, a retrospective review of all subjects' charts was conducted to identify patients who had had 24-hour pH tests, and the prevalence of IBS was determined in this subgroup. RESULTS: Of the 200 subjects, 90 ,45%, patients returned the questionnaire. After excluding subjects with IBD and incomplete questionnaires, there were 84 subjects, 35 with GERD, included in the analysis. Of the 35 GERD subjects, 25 71% were Rome I criteria positive for IBS, whereas only 17 of the 49 35% non-GERD subjects had IBS (odds ratio = 54.7, CI = 1.7-13.5, p < 0.01). In 11 of the GERD subjects a 24-hour pH study was available and confirmed GERD. Of these 11 subjects, 7 64% met Rome I criteria for IBS. CONCLUSION: There is a higher prevalence of IBS in subjects with GERD compared with subjects without GERD.