Rectoanal pressures and rectal sensitivity studies in chronic childhood constipation.

Rectoanal pressures and rectal sensitivity studies were performed in 32 control children and 144 chronically constipated children. The rectoanal inhibitory reflex threshold, the maximal anal resting closure pressure, and the conscious rectal sensitivity threshold were studied in these children. The rectoanal inhibitory reflex threshold was increased in 6.2% of the constipated patients. Anal hypertony (increased maximal anal resting pressure) was found in 46% of the constipated children. Decreased rectal sensitivity (increased conscious sensitivity threshold) was found in 68% of the constipated children. The three parameters were found to be normal in only 13% of the constipated subjects. Thus, it appears that children with chronic constipation who do not have Hirschsprung's disease do have abnormalities at manometry in most cases.