[An epidemiologic study of bowel habit in adult non-patient population in Beijing area]

To determine the bowel habit and its influencing factors in the adult non-patient population in Beijing area.

A questionnaire survey was conducted among 2486 adult permanent residents in Beijing area by randomized stratified sampling. The bowel habit (defecation frequency, characters of feces, time of defecation, and abnormal defecation) of the 1 952 non-patients among them were further investigated. The non-patient subject should fulfil the following criteria: (1) without gastrointestinal and hepatic organic diseases; (2) without metabolic disease affecting the motility of the gastrointestinal tract, such as diabetes mellitus and thyroid hyperfunction; (3) without irritable bowel syndrome which fits in the Manning criteria; and (4) considering oneself as having normal bowel habits.

84.17% of the non-patient interviewees defecated once per day with the mean defecation frequency of 7.09 times per week. 89.86% of the interviewees had formed or soft stool. 93.08% of the non-patients defecated formed or soft stool 3 to 21 times per week. No evidence showed that the frequency of defecation and character of feces were related to age and sex. 77% of them defecated in the morning. The prevalence rates of constipation, diarrhea, and abdominal pain associated with defecation were 3.74%, 1.08%, and 7.38% respectively.

The defecation frequency of adult nonpatient population in Beijing area is almost identical to that reported in the west. 93.08% of the non-patient subjects have normal defecation patterns. It is necessary to define the judgement criteria for constipation and diarrhea for Chinese based on their defecation patterns.