Anorectal manometry after Ikeda's Z-shaped anastomosis in Hirschsprung's disease

The intraluminal pressure of the rectum and anal canal were measured in patients with Hirschsprung's disease before and after Ikeda's Z-shaped anastomosis, and the association of the pressure with postoperative capability of fecal continence was assessed. Radical operation did not alter rectal pressure but did decrease anal-canal pressure. Rhythmical anal contractions increased in frequency until a normal level was attained. The rectoanal relaxation reflex became distinct with time, and 45% of patients eventually attained the reflex after operation. In patients who postoperatively attained satisfactory fecal continence or, at least, only soiling, resting pressure in the anorectum and the frequency of rhythmical anal-canal contractions were similar to those for normal children. The rectoanal relaxation reflex was induced in 58% of the former and 27% of the latter. In patients with postoperative constipation, the intraluminal resting pressure of the anorectum was elevated without the relaxation reflex response. In patients with incontinence, the pressure of the anal canal was low, without a reflex response. These findings indicate that the high and low values of the resting pressure of the anal canal are responsible for constipation and incontinence, respectively, and that the presence of rectoanal relaxation reflex may represent one aspect of a normal defecation function.