Postoperative sequential anorectal manometric study of children with Hirschsprung's disease.

When the rectum was distended artificially by a balloon, intraluminal pressure in the anal canal dropped in 30 normal children, but rose in 22 children with Hirschsprung's disease. This was independent of the length of aganglionosis. The average resting pressure in the anorectum in Hirschsprung's disease was higher than that of normal children. In patients who underwent coloproctectomy and Z-shaped anastomosis for Hirschsprung's disease, the rectosphincteric reflex was absent 1 mo after operation. Two months after surgery, however, the rectosphincteric reflex appeared in 77% of the patients. The patients who developed a rectosphincteric reflex had excellent continence, while some of those who did not show the reflex had incomplete continence or mild constipation.