Background: Gastro-oesophageal reflux disease and irritable bowel syndrome are common diseases, which may be related.
Aim: To assess the association between gastro-oesophageal reflux disease and irritable bowel syndrome in a country with high prevalence of Helicobacter pylori.
Methods: This study was designed as cross-sectional and population-based in Tehran province, Iran. The participants were interviewed by using a valid and reliable questionnaire. Gastro-oesophageal reflux disease was defined by weekly or more frequent heartburn and/or acid regurgitation. Irritable bowel syndrome was diagnosed according to the Rome III. The association between these two disorders was calculated using a statistical model that allows the odds ratio (OR) to be measured.
Results: A total of 6526 individuals were selected randomly, the response rate was 87.8%. Among the respondents, 178 (3.1%) participants reported both the diseases. The OR of having gastro-oesophageal reflux disease and irritable bowel syndrome together was estimated to be 16.55 (95% confidence interval: 12.85-21.33) indicating significant association between the two diseases. Thirty-four percent of patients with gastro-oesophageal reflux disease and 61.5% with irritable bowel syndrome suffered from both diseases. Sex did not have a significant effect on the OR of coexistence. Older participants were statistically more prone to the coexistence of two diseases.
Conclusion: The association between gastro-oesophageal reflux disease and irritable bowel syndrome was significantly higher in our community compared with others. Their association occurs predominantly in older participants. Further studies for understanding of the pathophysiological mechanisms behind these two diseases are required.