Anorectal manometry in the diagnosis of Hirschsprung's disease in adults.

: Anorectal manometry is a useful tool in evaluating the cause of chronic constipation and is reliable in the diagnosis of Hirschsprung's disease. Two adult patients ages 35 and 69 with constipation since birth underwent anorectal manometry. Balloons positioned at the internal and external anal sphincters were connected to pressure transducers and their responses to a distention of rectal balloon were recorded. Both patients demonstrated failure of relaxation of the internal anal sphincter which is characteristic of Hirschsprung's disease. This diagnosis was confirmed at surgery by histologic examination failing to show ganglia. Anorectal manometry is a useful adjunct in the differential diagnosis of adult patients with megacolon.