Prevalence and relationship between gastrointestinal symptoms among individuals of different body mass index: A population-based study.

Background: Obesity has been identified as a potential risk factor for gastrointestinal (GI) symptoms, although the data from community samples remain sparse. We assess the associations between GI symptoms and obesity in a population-based sample of Australian adults. Method: The prevalence of 26 GI symptoms was determined by a validated postal questionnaire which was sent to 5000 randomly selected residents. The response rate was 60%. GI symptoms were classified into six broader symptom groups based on the Rome II Criteria - abdominal pain, esophageal symptoms, dysmotility symptoms, diarrhea, vomiting, and constipation. Obesity was defined according to body mass index using self-reported height and weight.

Results: The prevalence of obesity (BMI≥30kg/m(2)) was 25.1%; 36.1% were overweight. There were significant and positive univariate associations between obesity and abdominal pain (OR=1.75; 95% CI: 1.39-2.21), esophageal symptoms (OR=1.74; 95% CI: 1.36-2.22), dysmotility symptoms (OR=1.43; 95% CI: 1.16-1.77) and diarrhea (OR=2.01; 95% CI: 1.65-2.45). The adjustment for socioeconomic characteristics and eating behaviors had minimal effect on the associations for abdominal pain (OR=1.34; 95% CI: 1.01-1.79), esophageal symptoms (OR=1.35; 95% CI: 1.03-1.78), and diarrhea (OR=1.86; 95% CI: 1.49-2.31); however, the association between obesity and dysmotility symptoms became non-significant. Obesity was not related to constipation.

Conclusion: Obesity is an independent risk factor for abdominal pain, esophageal symptoms and diarrhea, but is not associated with dysmotility symptoms or constipation.