An anorectal malformation is a birth defect that occurs when the anus and rectum do not develop correctly. The defect is characterised by an abnormally placed or completely absent anal opening. In the majority of boys with an ARM, the rectum will be connected to the urinary tract. In females it is usually closely related or connected to the genital tract. This congenital defect is often associated with defects affecting other organ systems. All babies with an anorectal malformation will require surgery. The type of surgery required will depend on the type of abnormality.