[Effectiveness of anorectal manometry using the balloon method to identify the inhibitory recto-anal reflex for diagnosis of Hirschsprung's disease].

OBJECTIVE

To evaluate results of anorectal manometry performed with equipment made in Brazil for the screening of Hirschsprung's disease in children with chronic constipation.

METHODS

Results of 372 anorectal manometries performed consecutively in children with chronic constipation were evaluated. The equipment (Proctosystem Viotti) has two channels for pressure registration by the balloon method and is connected to a computer using specific software. Absence of the inhibitory recto-anal reflex was considered suggestive of Hirschsprung's disease and diagnosis was confirmed by traditional diagnostic methods.

RESULTS

Absence of the inhibitory recto-anal reflex was found in 14 (3.8%) of the 372 anorectal manometry examinations. Diagnosis of Hirschsprung disease was confirmed in 9 out of 14 patients by characterization of aganglionosis upon rectal biopsy. In the other 5 patients, rectal biopsy was not performed in view of a satisfactory evolution with the clinical treatment for constipation. In 4 out of the 5 patients the inhibitory recto-anal reflex was demonstrated with a second anorectal manometry examination.

CONCLUSIONS

The equipment used for anorectal manometry presented a satisfactory performance. Diagnosis of Hirschsprung disease was discarded in 86.5% of the patients with chronic constipation because the inhibitory recto-anal reflex was detected. Manometric evaluation also made possible the identification of a small group of patients in which more than half had Hirschsprung's disease.