Rectoanal sphincteric inhibitory reflex and continence were evaluated in 23 patients with high and intermediate imperforate anus who underwent posterior sagittal anorectoplasty from 1985 to 1993. The postoperative anorectal function was followed both manometrically and clinically at regular intervals. The presence of the reflex was positively related to postoperative continence in patients older than 4 years but not in younger patients. Two patients with a rectoprostate fistula after an internal sphincter saving procedure had unsatisfactory results. Seven of nine patients with a blind rectal pouch, whose distal rectal end (where the internal sphincter lies) was partially excised or trimmed during reconstruction, had fair postoperative defecation. The internal sphincter saving procedure is helpful but it does not seem essential for the development of continence. The fact that patients with a negative reflex turned out to have a positive reflex 7 to 33 months after the initial test suggested that the rectum or perirectal tissue had recovered from surgical trauma. Time and age are important factors in clinical evaluation and interpretation of manometric results.