Obesity is associated with significantly increased risk for diarrhoea after controlling for demographic, dietary and medical factors: a cross-sectional analysis of the 2009-2010 National Health and Nutrition Examination Survey.

BACKGROUND

Obesity is associated with increased risk for various gastrointestinal and liver diseases. However, the relationship between obesity and abnormal bowel habits is poorly understood.

AIM

To investigate the relationship between body mass index (BMI) and bowel habit, controlling for clinical, demographic and dietary factors, in a representative sample of the United States adult population METHODS: Data were extracted from the 2009-2010 National Health and Nutrition Examination Survey. Survey responses were included in this study if respondents completed the bowel health questionnaire (BHQ), were ≥20 years of age, and did not report history of IBD, celiac disease or colon cancer. BMI was divided into the following categories: underweight, normal weight, overweight, obese and severely obese. Stepwise logistic regression provided risk ratios of constipation and diarrhoea controlling for confounding factors (dietary, life-style, psychological and medical).

RESULTS

A total of 5126 respondents completed the BHQ, had BMI data available, and met eligibility criteria. Of these, 70 (1.40%) were underweight, 1350 (26.34%) were normal weight, 1731 (33.77%) were overweight, 1097 (21.40%) were obese and 878 (17.13%) were severely obese. Up to 8.5% of obese and 11.5% of severely obese individuals had chronic diarrhoea, compared to 4.5% of normal weight individuals. Stepwise regression revealed that severe obesity was independently associated with increased risk of diarrhoea.

CONCLUSION

Obesity is positively associated with chronic diarrhoea in a nationally representative US adult population after adjusting for several known confounding factors.