The Association of Irritable Bowel Syndrome and Obesity in Iranian Adults

There were few researches indicating the association between irritable bowel syndrome (IBS) and obesity. This study aimed toassess the association of IBS with obesity and abdominal obesity.
During this cross-sectional study, 4763 Iranian adults filled out self-administered questionnaires on demographics and IBS. Data on self-reported height, weight and waist circumference were used to calculate body mass index and abdominal obesity. The prevalence and symptom frequency of IBS and its subtypes was evaluated in each subgroup. Modified Persian version of ROME III questionnaire was applied for this purpose.
Findings: We found that IBS was more prevalent in individuals with abdominal obesity compared with normal individuals (25% vs. 18%). Additionally, these people had a greater probability to have frequent symptoms even after adjustment for potential confounders although control for these factors attenuated this relationship (OR: 1.30, 95%CI: 1.04-1.63). IBS-Mixed was also observed to have more symptom frequency in people with abdominal obesity (OR: 2.71, 95%CI: 1.09-6.72). No significant association was observed between IBS and different BMI categories although obese people had a greater probability to be affected by IBS-Diarrhea (OR: 1.51, 95%CI: 0.98-2.30). Besides, we showed that overweight people reported more frequent symptoms of IBS-Diarrhea (OR: 2.51, 95%CI: 1.24-5.08).
Obesity whether in general or abdominal was associated with symptom frequency rather than prevalence of IBS in this group of adults. In addition, this association was more prominent between obesity and IBS-Diarrhea subtype.