The Association between Late-Onset Fecal Incontinence and Obstetric Anal Sphincter Defects

Hypothesis: Endoanal ultrasonographic results have demonstrated that clinically occult anal sphincter damage during vaginal delivery is common. This may or may not be associated with postpartum fecal incontinence (FI). Bayesian meta-analysis of the literature revealed that at least two thirds of obstetric sphincter disruptions are asymptomatic in the postpartum period. Women with post-partum asymptomatic sphincter damage may be at increased risk for FI with aging compared with those without sphincter injury. Design: Case series. Setting: Tertiary referral center. Patients: After excluding patients with other possible causes of FI, the histories of 124 consecutive women with late-onset FI after vaginal delivery were analyzed. Main Outcome Measures: Endoanal ultrasonographic findings, pudendal nerve terminal motor latency assessment, and anal manometric results. Results. Eighty-eight women (71%) with a median of 3 vaginal deliveries had sphincter defects on endoanal ultrasonographic results. The mean incontinence score, squeeze and resting pressures, median age at last delivery, and median duration of FI were not significantly different between patients with and without sphincter defects. Pudendal neuropathy was more frequent in patients without sphincter defects (10 [30.3%], left side; 12 [36.4%], right side) than in patients with sphincter defects (12 [14.3%] and 16 [19.3%], respectively), with the difference nearly reaching statistical significance (P=.054 and P=.059, respectively). The median age at onset of FI in patients with a sphincter defect was 61.5 years vs 68.0 years in those without a sphincter defect, which was not statistically significant (P=.08). Conclusion: Analysis of the current patient population revealed that 88 women (71%) with late-onset FI after vaginal delivery had an anatomical sphincter defect. Thus, FI related to anal sphincter defects is likely to occur even in an elderly population who had experienced vaginal deliveries earlier in life.