The rectoanal relaxation reflex and continence in repaired anorectal malformations with and without an internal sphincter-saving procedure.

From 1985 to 1994, 27 patients with high- or intermediate type imperforate anus who underwent anorectoplasty were studied for postoperative function, particularly with respect to the rectoanal relaxation reflex and continence. Fourteen of the patients had a rectourogenital fistula and were treated with posterior sagittal anorectoplasty using the fistular end as the neoanus (internal sphincter-saving). Nine patients had a blind rectal pouch and received posterior sagittal anorectoplasty using the trimmed bowel end for reconstruction of the neoanus (incomplete internal sphincter-saving). The other four had Rehbein's mucosa-stripping endorectal pull-through combined with anterior sagittal anorectoplasty (none internal sphincter-saving). A positive rectoanal relaxation reflex was found in 8 of 14 (57.1%), 7 of 9 (77.8%), and 3 of 4 (75%), respectively. It appears that the internal sphincter-saving procedure is not essential for the development of the rectoanal relaxation reflex. Compensation or adaptation most likely contributes to the presence of the rectoanal relaxation reflex, and perhaps to postoperative continence.