Congenital funnel anus.

Five patients (three children, two adults) with a congenital funnel anus are described. Congenital funnel anus is a rare anomaly; it was found in 3.5% of the children who were referred to Children's Hospital, University of Helsinki, for the treatment of low anorectal malformations between 1977 and 1993. Unlike the vast majority of patients with low anorectal anomalies, all of these patients had a huge megacolon, with consequent constipation that was refractory to conservative treatment. Resection of the dilated part of the colon and low coloanal anastomosis relieved the severe constipation in all patients.