Bowel Disturbances Are the Most Important Risk Factors for Late Onset Fecal Incontinence: A Population-Based Case-Control Study in Women

Abstract

Age, diarrhea, and certain chronic illnesses are risk factors for fecal incontinence (FI). However, the contribution of obstetric injury to the development of FI later in life is unclear. We sought to better understand the risk factors for FI. Through the Rochester Epidemiology Project, a nested case-control study of 176 randomly selected women with FI (cases; mean age, 58 years) and 176 age-matched community controls was conducted in a population-based cohort from Olmsted County, Minnesota. Risk factors for FI were evaluated by reviewing inpatient and outpatient medical (including original obstetric) records. Analyses focused on conditions that preceded the index date (incidence date of FI for case in each matched pair). In 88% of cases, FI began at age ≥40 years; severity was mild (37%), moderate (58%), or severe (5%). By multivariable analysis, current smoking (odds ratio [OR], 4.7; 95% confidence interval [CI], 1.4-15), body mass index (OR per unit, 1.1; 95% CI, 1.004-1.1), diarrhea (OR, 53; 95% CI, 6.1-471), irritable bowel syndrome (OR, 4.8; 95% CI, 1.6-14), cholecystectomy (OR, 4.2; 95% CI, 1.2-15), rectocele (OR, 4.9; 95% CI, 1.3-19), and stress urinary incontinence (OR, 3.1; 95% CI, 1.4-6.5), but not obstetric events, were independent risk factors for FI. Bowel disturbances rather than prior obstetric injury are the main risk factors for FI. Measures to ameliorate bowel disturbances and other potentially reversible risk factors should be implemented before anal imaging is performed on women with FI.