Randomized, Clinical Trial of Bowel Confinement vs. Laxative Use After Primary Repair of a Third-Degree Obstetric Anal Sphincter Tear

PURPOSE: Third-degree tears are generally managed by primary anal sphincter repair. Postoperatively, some physicians recommend laxative use, whereas others favor bowel confinement after anorectal reconstructive surgery. This randomized trial was designed to compare a laxative regimen with a constipating regimen in early postoperative management after primary obstetric anal sphincter repair. METHODS: A total of 105 females were randomized after primary repair of a third-degree tear to receive lactulose (laxative group) or codeine phosphate (constipated group) for three days postoperatively. Patients were reviewed at three days and at three months postpartum. Recorded outcome measures were symptomatic and functional outcome and early postoperative morbidity. RESULTS: Forty-nine patients were randomly assigned to the constipated group and 56 patients to the laxative group. The first postoperative bowel motion occurred at a median of four (mean, 4.5 (range, 1–9)) days in the constipated group and at two (mean, 2.5 (range, 1–7)) days in the laxative group (P < 0.001). Patients in the constipated group had a significantly more painful first evacuation compared with the laxative group (P < 0.001). The mean duration of hospital stay was 3.7 (range, 2–6) days in the constipated group and 3.05 days in the laxative group (range, 2–5; P = 0.001). Nine patients in the constipated group complained of troublesome postoperative constipation compared with three in the laxative group (P = 0.033). Continence scores, anal manometry, and endoanal ultrasound findings were similar in the two groups at three months postpartum. CONCLUSIONS: Patients in the laxative group had a significantly earlier and less painful bowel motion and earlier postnatal discharge. There was no difference in the symptomatic or functional outcome of repair between the two regimens.