Changes in fatigability of the striated anal canal after childbirth

Abstract

Aim: Anal manometry is an established assessment tool for patients with faecal incontinence. Fatigue rate index (FRI) has been shown to discriminate between symptomatic patients and controls. The aim of this study was to compare manometry and fatigability of the anal canal in nulliparous women before and after childbirth.

Method: An air-filled manometry device was used to record maximum resting and squeeze pressures, fatigue rate (recorded over 20 s) and FRI. Recordings were made before and after vaginal delivery.

Results: Nineteen women were studied. Resting anal canal pressure was not significantly different before and after delivery (57.1 +/- 13.6 vs 51.1 +/- 11.9 cmH(2)O, P = 0.1). Squeeze pressure was significantly lower postpartum (106.5 +/- 43.6 vs 75.5 +/- 45.6 cmH(2)O, P < 0.001). Fatigue rate was significantly reduced postpartum (-129.5 +/- 74.7 vs-76.1 +/- 54.8 cmH(2)O/min, P = 0.001), but FRI was not significantly altered (1.23 +/- 1.49 vs 1.41 +/- 1.27 min, P = 0.09).

Conclusion: Maximal squeeze pressure and fatigue rate of the anal canal are significantly reduced after childbirth. Resting anal canal pressure and FRI are not significantly different.