GoalsTo determine the prevalence of irritable bowel syndrome (IBS) in subjects with gastroesophageal reflux disease (GERD) compared with non-GERD controls.StudyTwo 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.ResultsOf 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.ConclusionThere is a higher prevalence of IBS in subjects with GERD compared with subjects without GERD.