The authors present an overview of 101 patients operated for Hirschsprung's disease by Rehbein procedure. Special attention is directed to the histomorphological findings in the proximal segment of the resected bowel specimens. A strong link was confirmed between these specific features and postoperative bowel function. A histologically regular proximal bowel segment generally predicted good postoperative bowel function with a constipation rate of 10.5%. In patients with intestinal neuronal dysplasia (IND) of the proximal segment the overall clinical result remained unchanged, although the constipation rate rose to 17.8%. Postoperative bowel function was seriously affected in cases characterized by proximal segment hypoganglionosis with a constipation rate of 23.1% and an additional 7.7% with encopresis. Finally, the distinct group of children with aganglionosis of the proximal segment followed a complicated postoperative course with secondary bowel resections and recurrent episodes of enterocolitis. In addition, the authors state their general observation that histological findings become less important whenever a more extensive resection than left hemicolectomy is required. Discussing the results, guidelines are given to further patient treatment once the particular proximal segment histology is diagnosed.