Anorectal manometry: a new simplified technique.

Several noninvasive techniques using anal balloons or catheter systems to measure anal sphincter function associated with rectal balloon distention have been used in differentiating functional constipation from aganglionic megacolon. We have developed a simplified method for anorectal manometry that uses a microtip pressure transducer to record anal sphincter responses. Seventy-three patients (51 children and 22 adults) with constipation have been studied with this technique. Normal responses of internal anal sphincter relaxation to rectal distentions were obtained in 60 patients (40 children and 20 adults), consistent with the diagnosis of functional constipation. Abnormal responses-no internal anal sphincter relaxation-were recorded in 13 patients (11 children and two adults), consistent with the diagnosis of Hirschsprung's disease. The manometric diagnosis was confirmed in all 21 patients biopsied. There were no false-positive or false-negative results. The technique is a simple, well tolerated, and rapid method for assessing anal sphincter function.