Prevalence of irritable bowel syndrome and functional dyspepsia, overlapping symptoms, and associated factors in a general population of Bangladesh

Background This community-based survey aimed to find out the prevalence of irritable bowel syndrome (IBS), functional dyspepsia (FD), overlapping symptoms, and associated factors for overlap. Method By cluster sampling method, 3,000 (1,523 male) randomly selected adult subjects in the Sylhet district of Bangladesh were interviewed by a questionnaire based on ROME III criteria. Multivariate logistic regression analyses were done to find out the factors for overlap with significance level set at <= 0.05. Results The mean age of the study population was 33.9 +/- 16.4 years. Prevalence of IBS and FD and IBS-FD were 12.9 % (n = 387), 8.3 % (n = 249), and 3.5 % (n = 105), respectively. Approximately 27.1 % of IBS patients and 42.1 % of FD patients had overlapping IBS-FD. The odds ratio for IBS-FD overlap was 6.3 (95 % CI, 4.8-8.4). Mean age (p = 0.011) and epigastric pain (p = 0.002) were more in overlap patients than FD alone, whereas epigastric pain syndrome subtype (p < 0.009) was more prevalent in lone FD subjects. In the multivariate logistic analysis, early satiety (OR, 3.0; 95 % CI, 1.2-7.5; p = 0.018) and epigastric pain (OR, 14.5; 95 % CI, 5.0-42.1; p= 0.000) in FD patients appeared as independent risk factors for overlap. Bloating (p = 0.026), < 3 stools per week (p = 0.050), abdominal pain reduced by defecation (p = 0.002), abdominal pain severity score (p= 0.004), and overall symptom frequency score (p = 0.000) were more in overlap patients than IBS-alone patients. In IBS patients, bloating (OR, 3.6; CI, 2.0-6.5; p = 0.000) was found as potential symptom associated with IBS-FD overlap. Conclusion FD was a less prevalent disorder than IBS in our community, and significant overlap existed between the two disorders. Early satiety, epigastric pain, and bloating were important factors associated with overlap.