Importance of evacuatory disturbance in evaluation of faecal incontinence after third degree obstetric tear

Abstract

Objective: To correlate anorectal function including rectal evacuation with anorectal physiology and endoanal ultrasound in women with third degree obstetric anal sphincter injury repaired at the time of delivery.

Patients and methods: Forty-four women with repaired third degree tears underwent anorectal physiology, anal ultrasonography and clinical assessment using the St. Marks incontinence score (0-24). Evacuatory disturbance was assessed by questionnaire.

Results: There was a significant correlation between disturbed evacuation and incontinence symptoms (P=0.030). There was also a significant correlation between disturbed evacuation and internal anal sphincter (IAS) injury (P=0.026), but there was no correlation with external anal sphincter (EAS) injury. There was a correlation between disturbed evacuation and low resting anal pressure (P=0.013). Although IAS defects were associated with low anal pressure, only the correlation with Maximum Squeeze Pressure reached statistical significance (P=0.018).

Conclusion: Women with evacuatory disturbance after repaired third degree tears have a greater level of incontinence than those whose emptying is normal. This association is related to internal sphincter injury and reduced anal sphincter pressures.