Anal incontinence in women with and those without pelvic floor disorders

OBJECTIVE: To compare the prevalence of anal incontinence and anal sphincter injury in women with pelvic floor disorders (cases) with those in a group of normal control subjects and to evaluate the relationship between sphincter injury and anal incontinence in each group. METHODS: We previously reported the results of a cross-sectional study of 100 women with pelvic floor disorders (>= stage II pelvic organ prolapse and/or urinary incontinence). In this study, we compared those cases with 90 controls (stage 0 or I pelvic organ prolapse and no urinary incontinence) who completed the Rockwood-Thompson fecal incontinence severity index, in which scoring (0-61) is based on the frequency and type of anal incontinence. All women underwent endoanal ultrasonography, and the internal and external anal sphincters were reported as intact versus disrupted. Chi-square test, Student t test, and logistic regression were used for statistical analysis. RESULTS: Women with pelvic floor disorders were significantly more likely to report anal incontinence (54% versus 17.8%, odds ratio [OR] 5.4, 95% confidence interval [CI] 2.8-10.6, P < .001) and had higher mean fecal incontinence severity index scores (22.3 +/- 13 versus 12.7 +/- 6.3, P = .006) than controls. Cases demonstrated higher rates of anal sphincter defects on ultrasound examination than did controls (52% versus 30%, P = .007). Anal incontinence was significantly associated with anal sphincter injury in women with pelvic floor disorders (OR 36.4, 95% Cl 12-114, P < .001) and in controls (OR 5.9, 95% Cl 3-11, P = .002). CONCLUSION: Anal incontinence was more common in women with pelvic floor disorders than normal controls and may be due to higher rates of anatomic anal sphincter disruption in this group.