One hundred seventy-eight of 326 patients had surgery for Hirschsprung's disease at Red Cross Children's Hospital (1957 to 1990) agreed to participate in a recall follow-up study. Assessment of the postoperative outcome of the Swenson, Duhamel, and Soave procedures included manometric evaluation in 43 patients by perfused-tube and balloonseries techniques. Rectal suction biopsies were performed for patients who had persistent problems with stool evacuation. One hundred fifteen of the 178 patients were more than 4 years of age, and long-term functional outcome could be assessed. Although good results were obtained in 94% overall, 16 had clinical evidence of a degree of perrsisting obstruction. Results of manometric assessment of anorectal function in these patients were not significantly different from those of 28 patients who had normal stool evacuation. A biopsy was performed in 14 of the 16 patients who had symptoms of obstruction postoperatively, and abnormal histological features were noted. There was aganglionosis in four, features of neuronal intestinal dysplasia in nine, ganlioneuromatosis of the colon in one. The results of two biopsies were entirely normal. Implications of Postoperative dysfunction after surgery for Hirschsprung's disease are discussed, and a protocol for investigation and management is proposed.