Postanal sphincter repair for anterior resection anal sphincter injuries: report of three cases.

Treatment options are limited for intractable excessive stool frequency and incontinence after low anterior resection for rectal cancer. Fortunately, this is quite rare, but three such patients were reported. The patients did not respond to two years of expectant treatment, including medications and anorectal biofeedback. Anorectal physiologic tests and endoanal ultrasound findings were consistent with internal anal sphincter injuries, which are known to occur with transanal insertion of stapling instruments. After postanal sphincter repair, stool frequency was reduced from 5.7 (standard error of the mean, 1.3) to 1.7 (0.3) stools per day. Fecal incontinence requiring pads in all patients was reduced to full continence in two patients and gas incontinence in one. Continence score improved from 13.7 (2.2) to 1.3 (0.3). Mean follow-up was 3.2 (0.5) years. Postanal sphincter repair could be considered when persistent bowel dysfunction after anterior resection is caused by internal sphincter injury.