The prevalence of faecal incontinence and constipation in a general New Zealand population; a postal survey

Abstract

Aims: To determine the prevalence of constipation and faecal incontinence in the community.

Methods: A 20-question multi-field postal questionnaire was sent to 1500 adults (over 18 years) randomly selected from the electoral roll in the Canterbury region. Questions detailed frequency of bowel function, time spent at the toilet, incidence and severity of faecal incontinence, constipation, and the effect of disordered bowel function.

Results: Of 1500 questionnaires, 717 (48%) were returned (male: female 388:329). The median age was 46 years (range 18-70). 24 (4%) had self-reported gastrointestinal disease. There was a median frequency of seven bowel motions per week (BM/wk) (range 1 to 70) with 89% having between two motions a day and one every two days. Faecal incontinence affected lifestyle in 58 (8.1%). Incontinence of solid stool at least once a month occurred in 70 (9.8%), of liquid stool in 91 (12.7%), of gas in 459 (64%), while 12 (2%) regularly wore a pad. Those with self-reported gastrointestinal disease had a significantly higher (p<0.05) bowel motion frequency (17 vs 7 BM/wk) and median faecal incontinence score (2.5 vs 0). Laxatives were used by 4.9% of the population, while 26.2% increased fibre to avoid constipation.

Conclusions: The normal frequency of bowel motions (+/- 2SD) was 2-17 per week. Faecal incontinence affecting life style affected 8.1%, while constipation requiring regular laxative use affected 4.9% of people. There is acceptance in the community that a moderate degree of bowel dysfunction is normal. Stool frequency and faecal incontinence scores can be used to predict those most likely to have organic gastrointestinal disease.