Obesity and functional constipation; a community-based study in Iran.

BACKGROUND Many factors have been linked to the occurrence of constipation, but few studies exist regarding the link between obesity and constipation. The aim of this study was to assess the association between body mass index (BMI) and functional constipation in the Iranian community. METHODS From May 2006 to December 2007, a cross sectional study was conducted in the Tehran province and a total of 18,180 adult persons were drawn up randomly. One questionnaire was filled in two stages through interviews. In the first part, personal characteristics and 11 gastrointestinal symptoms were listed. Those who reported at least one of these 11 symptoms were referred for the second interview. The second part of the questionnaire consisted of questions about different gastrointestinal disorders based on the Rome III criteria including functional constipation. RESULTS 459 adult persons were found to have functional constipation. The mean +/- SD of BMI was 26.5 +/- 4.7 and 60% of the patients had a BMI more than 25. Age and education were significantly associated factors with obesity, showing that older patients and less educated patients were more overweight and obese. Smoking, marital status and sex were not significantly associated with obesity but, up to 60% of low educated women who had functional constipation, had a BMI more than 25. CONCLUSIONS Our study showed that about 60% of patients with functional constipation were overweight, which was more than the mean of our community. In addition there may be an association between higher BMI level and the low education level with constipation in Iranian women.