Anorectal malformations are a wide group
of malformations characterized by an
abnormal anal opening. Most often detected
at birth, this abnormality can range from
stenosis of the normally sited opening, to an
abnormal position of the anus, to complete
absence of the anus. Associated with the
apparent problem with the anus, are a range
of local abnormalities affecting the rectum
and the adjacent genitourinary system. These
are most often fistulas between the rectum
and the urinary tract in males, and the
reproductive tract in females. The most
bizarre manifestations are the variations
seen in the most severe of the female
malformations, the common cloaca, where the
lower urinary tract, the uterus and vagina
and the anorectum are fused in an array of
combinations.