Non-fixation of the colon in colonic atresia: a new finding.

Colonic atresia is a rare cause of congenital bowel obstruction. We have recently encountered two neonates with colonic atresia in whom the colon was displaced entirely to the midline on contrast enema examination. At surgery both patients had type III atresias (blind ends with a mesenteric defect), and were found to have non-fixation of the colon, accounting for its unusual midline positioning. This has not been previously described in the literature. In addition, one of the patients had a stormy post-operative course due to unsuspected Hirschsprung's disease. This represents the eighth case of associated colonic atresia and Hirschsprung's disease in the literature.