Anorectal manometry: experience with strain gauge pressure transducers for the diagnosis of Hirschsprung's disease.

An esophageal pressure transducer with three strain gauges was used in the anal canal to study the rectosphincteric reflex (RSR) in five infants and children with intestinal obstruction, 142 children age one day to 18 years with moderate to severe constipation and in 18 healthy control children 4 to 12 years of age. The RSR was present in the four newborns with intestinal obstruction in 133 of the constipated children, and in all healthy controls. The mean (+/- SD) minimal volume of air in the rectal balloon required to produce RSR greater than or equal to 5 mm Hg (RSRT) was 9 mL (+/- 2) for infants 0 to 2 years, 14 mL (+/- 4) for children 2 to 4 years, 15 mL (+/- 6) for children 4 to 12 years, and 14 mL (+/- 6) for children 12 to 18 years of age. The RSRT for control children was 13 mL (+/- 4). The volume of air used in rectal balloon distension correlated with the amplitude of the RSR for control (r = 0.7131) and constipated children (r = 0.6289). The amplitudes of the RSR for the controls were significantly higher than the amplitudes for constipated children for rectal distension volumes between 60 and 15 cc (p less than 0.01). The 10 children with absent RSR had Hirschsprung's disease confirmed at surgery. Measurements of RSR could be used to separate patients with chronic constipation from patients with Hirschsprung's disease.