Accuracy of anorectal manometry in the diagnosis of Hirschsprung's disease.

The value of anorectal manometry as a diagnostic tool for Hirschsprung's disease (HD) was assessed in 50 children presenting with chronic constipation. Anorectal manometric studies and rectal biopsy were performed on all children. Biopsy specimens were stained with hematoxylin and eosin and serial sections were examined for ganglion cells. Forty-five children had concordant manometric and histologic results, 15 of whom were positive for HD and 30 negative. In five children, the results were discordant. Using histologic aganglionosis as the reference point for the final diagnosis of HD, the overall accuracy of anorectal manometry as a discriminative test was 90.0%. The sensitivity, specificity, and positive and negative predictive values of manometric studies for the diagnosis of HD were 0.79, 0.97, 0.94, and 0.88, respectively. Factors responsible for the inaccuracies of manometric studies are discussed.