Anterior ectopic anus: a common cause of constipation in children.

Anterior ectopic anus is increasingly being recognized as a cause of constipation in infancy. Experience is reported with surgical treatment of 20 patients with anterior ectopic anus. This form of anal ectopia is associated with a syndrome of constipation that begins at birth, straining on defecation, and anterior displacement of an otherwise normal anus and sphincter. It is seen almost exclusively in females. Posterior anoplasty with sphincterotomy is curative.