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.