In one-stage transanal endorectal pull-through operation (TERPT) for Hirschsprung disease, preoperative evaluation by contrast enema (CE) is important tool in aspect of planning of surgical procedure as well as diagnosis. This study was to evaluate the significance of CE for identifying the extent of aganglionic bowel. A retrospective analysis was performed in 40 patients who underwent TERPT between 2003 and 2011. The authors reviewed the CE studies and their correlation with pathologic extent of aganglionosis. Total 66 contrast enemas were performed in 40 patients. Twenty patients underwent single CE, but 20 patients required multiple CEs. In single CE group, 17 had clear radiographic transition zone, but 3 had less definite transition zone. In multiple CE group, 17 patients who had equivocal finding in first or second CE had definite radiographic transition zone, but 3 patients of this group had less definite radiographic transition zones. Overall, 34 patients (85%) had clear radiographic transition zone by single or repeated CE. One (2.9%) out of 34 patients with clear radiographic transition zone had discordance between radiographic and pathologic transition zone. In contrast 4 (66.7%) out of 6 patients with equivocal radiographic transition zone had discordance between radiographic and pathologic transition zone. Observation of clear radiographic transition zone is important in preparation of TERPT, and repeated CE is helpful to reduce the discordance between radiographic and pathologic transition zone. Awareness of the possibility of discordance is also important if radiographic transitional zone is not clear.

Meconium obstruction (MO) in neonates arises from highly viscid meconium and the poor motility of the premature gut. Recently the incidence of the MO in neonates has been increasing, but, the diagnosis and treatment of this disease have not yet been clarified. Between March 2004 and April 2010, 24 neonates were treated for MO at Severance Children's Hospital. Their clinical characteristics and treatment were reviewed retrospectively. Twenty neonates were diagnosed with MO and 4 neonates were diagnosed with Hirschsprung's disease (HD). The mean birth weight and gestational age of the 20 neonates with MO were 1.45±0.90kg and 31.1±4.6 weeks, respectively. Thirteen neonates (65%) diagnosed with MO weighed less than 1.5kg and 10 neonates (50%) weighed less than 1kg. Half of the neonates with MO were treated by non-operative methods and the other half were treated by operative methods. Compared with the group that weighed over 1.5kg, the group that weighed less than 1.5kg were more frequently operated upon (61.5% vs. 28.5%), and contrast enemas were performed later and more frequently. Also the group that weighed less than 1.5kg had a higher mortality rate (15.4% vs. 0%). Three of the four neonates with HD were diagnosed with long-segment aganglionosis. In conclusion, MO occurred in very low birth weight neonates more often and must be differentiated from HD. Also, MO in very low birth weight neonates should be treated with special attention due to more a complicated clinical course.