Irritable bowel syndrome (IBS) and gastro-esophageal reflux-type symptoms (GERS) are highly prevalent in the general population, and the two appear to be related. We conducted a systematic review and meta-analysis to estimate the prevalence of GERS in individuals with IBS, and to quantify the overlap between the two disorders.
MEDLINE, EMBASE, and EMBASE Classic were searched (up to October 2011) to identify population-based studies reporting the prevalence of IBS and GERS in adults (≥15 years), defined using a specific symptom-based criteria or a questionnaire. The prevalence of IBS and GERS were extracted for all studies. Pooled prevalence, according to study location and criteria used to define IBS or GERS, as well as odds ratios (OR), with 95% confidence intervals (CIs) were calculated. The degree of overlap between the two was examined.
Of 390 papers evaluated, 81 reported prevalence of IBS. Thirteen of these, containing 49,939 participants, reported the proportion of individuals with GERS. The prevalence of GERS in IBS was 42.0% (95% CI, 30.0–55.0). The pooled OR for GERS in individuals with IBS, compared with those without, was 4.17 (95% CI, 2.85–6.09). The OR for GERS in IBS remained significantly higher in all geographical regions studied, and for all diagnostic criteria used. The degree of overlap between the two conditions varied from 14.2, when the Rome II criteria for IBS were used, to 26.7% with the Manning criteria.
The OR of GERS in individuals with IBS was four-fold that of individuals without IBS. Reasons for this remain speculative, but may include shared pathophysiological mechanisms or residual confounding.