Introduction: Idiopathic constipation is a source of significant morbidity in children. A subset of patients is refractory to medical therapy and requires surgical intervention. We present a novel surgical technique for the management of these patients. Methods: We reviewed the records of 288 patients with severe idiopathic constipation and soiling. Patients who were refractory to medical management and had a megarectosigmoid underwent a transanal full-thickness rectosigmoid resection with a primary colo-anal anastomosis. Results: Fifteen patients underwent a transanal rectosigmoid resection. The preoperative contrast enema demonstrated an enormously dilated rectosigmoid in 14. An average of 43 cm (range, 8-98 cm) of rectosigmoid was resected. Of 14 patients with more than 3 months of follow-up, the preoperative laxative dose was 68 mg of senna/d (range, 52-95 mg), which decreased to 8.6 mg postoperatively (P < .001). Nine patients are clean without soiling, 1 is more prone to diarrhea, but is clean. Two patients soil occasionally, but are noncompliant, and 2 were lost to follow-up. Conclusion: Transanal rectosigmoid resection for medically intractable idiopathic constipation resulted in a dramatic reduction or elimination in laxatives use while preserving continence. It is a useful alternative to surgical options such as other colonic resections, antegrade enemas, and stomas. © 2009 Elsevier Inc. All rights reserved.