Imperforate anus is an abnormality present at birth, and characterized by the absence of the normal opening of the anus. Elimination of feces may not be possible until surgery is performed. In some cases the rectum opens into the lower part of the vagina in females, or close to the scrotum in males.

Imperforate anus, also called an anorectal malformation, is a rare birth defect that includes the absence of a normal anal opening (anus). Imperforate anus is usually diagnosed shortly after birth by a routine physical exam. The exact cause of these anal malformations is unknown. During a bowel movement, stool passes from the large intestine to.