Onset and risk factors for fecal incontinence in a US community.

Objectives: The natural history of fecal incontinence (FI) in community subjects is uncertain and the onset rate is unknown. The aim of the study is to estimate the prevalence, new-onset rate, and risk factors for FI in community subjects.
Methods: A random sample of 2,400 community subjects aged > or =50 years was surveyed in 1993, using a validated questionnaire. Responders were recontacted in 2003. FI was defined as self-reported problems with leakage of stool. Onset rate was calculated as the proportion of subjects without FI who became new cases. Logistic regression models were constructed to identify predictive factors for developing FI and changes in bowel habit associated with the onset of FI.
Results: Overall, 1,540 (64%) subjects responded to the initial survey, and 674 (44%) of them responded to the second survey a median of 9 (8.8-9.5) years later. The prevalence of FI in the first survey was 15.3% (13.4-17.3%). In the second survey, 37 reported incident FI; thus, the onset rate of FI was 7.0% (5.0-9.6) per 10 years. Predictive factors at baseline for the onset of FI were self-reported diarrhea (odds ratio (OR)=3.8 (1.5, 9.4)), incomplete evacuation (OR=3.4 (1.2, 9.8)), and pelvic radiation (OR=5.1 (1.01, 25.9)). Development of urgency was the primary predictor among the set of predictors reflecting changes in bowel symptoms that were associated with the onset of FI (OR=24.9 (10.6, 58.4)).
Conclusions: The onset rate of FI is approximately 7% per 10 years in community subjects aged > or =50 years. Prevention may be possible if bowel habit is appropriately managed in high-risk individuals.