The transanal endorectal pull-through (TAEPT) procedure is now widely performed for Hirschsprung's disease (HD), however, the colorectal function after TAEPT has not yet been adequately assessed. We evaluated the postoperative clinical outcome and colorectal function based on lower colonic manometry after TAEPT. Twenty-one cases of HD underwent TAEPT from 1998 to 2005. We examined the clinical outcome based on the requirement of enemas/suppositories, the number of defecations per day, the severity of perianal erosion, and the incidence of enterocolitis requiring hospital stay. Using a three-channel Dentsleeve catheter and UPS-2020 measuring device, we performed postoperative colonic manometry at three locations: (1) the anal canal, (2) 5 cm proximal to the anal canal, and (3) 10 cm proximal to the anal canal, during defecation, and then we measured the appearance of high-amplitude contraction (HAC) (duration >/=10 s, amplitude >/=100 cmH(2)O). Four of 21 cases were treated with enemas/suppositories no longer than 1 year. The number of defecations decreased gradually from 4 to 5 per day in the early postoperative period, reaching 2 to 3 per day about 1 year postoperatively. Perianal erosion was noted in 3 of 21 cases but it disappeared within three postoperative years. Two cases had enterocolitis. Lower colon manometry was performed in eight cases. Manometry during defecation was successfully monitored in six cases. HAC occurred in five of six cases (83.3%). The clinical outcomes after TAEPT were satisfactory in almost all cases. These good outcomes were possibly due to the occurrence of HAC during defecation, though HAC did not fill the definition of high amplitude propagated contractions (HAPCs). The occurrence of HAC after TAEPT might be caused by keeping any damage to the mesenteric ascending cholinergic nerve to a minimum during surgery. Further long-term observations are still required to make an adequate assessment of such cases.