Objective To evaluate the outcomes of transanal coloanal pull-through with resection of the internal anal sphincter in neonates and infants with Hirschsprung's disease.Methods Transanal coloanal pull-through with resection of the internal anal sphincter was performed on 101 neonates or infants with Hirschsprung's disease in our hospital.An incision slightly longer than one-half of the rectal circumference was made at the dentate line.Then,the muscular layer of the anterior rectal wall was dissected and separated upwards from the submucosal layer;meanwhile that of the posterior wall was also separated upwards along the rectal longitudinal muscles.After the muscular layer was separated to the level of the peritoneal reflection,a radial operation was performed by resecting the internal anal sphincter and muscle sheath of the posterior rectal wall.Results The operation was accomplished successfully in all the patients with less than 10 ml of intraoperative blood loss.The operation time ranged from 45 to 190 min(mean,90 min).No complications,including urine retention,incision infection,and anastomotic stenosis,occurred.Two patients(2/86,2.3%) developed enterocolitis after the operation.The incidence of fecal soiling was 27%(22/82) at 2 months after the operation,and then decreased to 4%(3/82) at 6 months.Anorectal manometry was performed on 78 patients at 1,2,3,and 6 months postoperatively.The results demonstrated that the anal resting pressure after the operation was significantly lower than that before the operation(P