Inquiries were conducted to determine the prevalence of anal incontinence in a) the general population over 45 by a gallup poll studying 1,100 persons (A); b) 3,914 patients seen by their general practitioner or their gastroenterologist during the same week (B); c) 500 patients consulting for urinary stress incontinence (C1); d) 1,136 neurological patients suffering from micturation disorders (C2); and e) 10,157 elderly persons living in retirement homes or in hospital (D). In the general community (A), the prevalence of anal incontinence, including gas and stool incontinence, was 11 percent, the prevalence of fecal incontinence, 6 percent, the prevalence of daily or weekly fecal incontinence, 2 percent; prevalences were respectively 15.5 percent, 7.9 percent, and 3.2 percent in group B, and 27 percent, 9 percent and 3.8 percent in group C1. The prevalence of fecal incontinence was 18 percent in group C2 and 33 percent in group D. Prevalence did not depend on age in group A and C1, but was twofold higher in group C1 than in group A. The prevalence increased with age in groups B and D.