[Usefulness of anorectal manometry in the neonatal diagnosis of Hirschsprung disease].

During 1992 through 1998 anorectal manometry studies have been carried out on 32 newborn, with age between 48 hours and 28 days and weight range of 1,400 and 4,200 g at the test moment. The test has been prescribed due to a retard in meconial evacuation in the 32 patients, moreover, 13 out of them also presented an intestinal obstruction or subobstruction. The anorectal manometry is carried out with a probe especially designed by us for newborn and a Hellige polygraph. Presence or absence or rectoanal inhibitory reflex (RAIR) is assessed. The test is repeated after one and three weeks from the first study in the cases of RAIR absence. A barium enema was carried out in case of RAIR absence. The RAIR was present in 20 out of the 32 newborn, which allowed the exclusion of Hirschsprung's disease (HD) in these patients. Of the remaining 12 patients, in 11 it was shown the absence of RIAR in the first anorectal manometry study, making it possible the early diagnosis of HD in 9 patients and transient functional obstruction of the colon in 2 newborns. This former diagnosis was corroborated by the findings of the enema, which showed a small left colon and by the presence of RAIR in a later anorectal manometry control. There was a doubtful case in the first study, showing later the absence of RAIR. The first enema in 10 newborn with HD was considered normal in 3 cases and with transitional zone in 4 newborns and microcolon in 1 case.