Colonic motility in children with repaired imperforate anus.

Following surgical correction of imperforate anus, voluntary bowel control is frequently poor because of abnormal anorectal function. Using colonic manometry we investigated the role of colonic motility in the pathogenesis of fecal soiling in children following imperforate anus repair. Thirteen children with repaired imperforate anus and fecal soiling underwent motility testing 2-12 years after anoplasty. All had fecal incontinence unresponsive to conventional medical treatment. Colonic manometry was performed using water-perfused catheters. Anorectal manometry was undertaken in 10 patients. Motility study results, treatment and outcomes were compared. All patients had high-amplitude propagating contractions (HAPCs) with an average of 80% propagation into the neorectum. There was no correlation between HAPC number or morphology and any variable. Internal anal sphincter resting pressure was low in 6/10 patients. Relaxation of the internal anal sphincter was present in 6/10 children. Only 1 of 5 patients able to cooperate was capable of generating a normal maximal squeeze pressure. Therapeutic regimens were changed in 11 patients with clinical improvement in five. Fecal soiling in patients with repaired imperforate anus is a multifactorial problem including propagation of excessive numbers of HAPCs into the neorectum as well as internal anal sphincter dysfunction. Colonic manometry in conjunction with anorectal manometry aids in the understanding of the pathophysiology of fecal soiling and guides clinical management in children with repaired imperforate anus.