Obesity is associated with increased risk of gastrointestinal symptoms: a population-based study.

Objectives: Perception of sensations arising from the gastrointestinal tract may be diminished in obese subjects and thus facilitate overeating. Alternatively, excess food intake may cause gastrointestinal (GI) symptoms in obese patients. We evaluated the relationship between body mass index (BMI) and specific GI symptoms in the community.
Methods: Residents of Olmsted County, MN were selected at random to receive by mail one of two validated questionnaires. The association of reported GI symptoms with BMI (kg/m(2)) was assessed using a logistic regression analysis adjusting for age, gender, psychosomatic symptom score, and alcohol and tobacco use.
Results: Response rate was 74% (1,963 of 2,660). The prevalence of obesity (BMI > or = 30 kg/m(2)) was 23%. There was a positive relationship between BMI and frequent vomiting (p= 0.02), upper abdominal pain (p= 0.03), bloating (p= 0.002), and diarrhea (p= 0.01). The prevalence of frequent lower abdominal pain, nausea, and constipation was increased among obese (BMI > or = 30 kg/m(2)) compared to normal weight participants, however, no significant association was found between BMI and these symptoms.
Conclusions: In the community, increasing BMI is associated with increased upper GI symptoms, bloating, and diarrhea. Clarification of the cause-and-effect relationships and the mechanisms of these associations require further investigation.