Diagnosis of imperforate anus (the absence of a normal anal opening)is usually made shortly after birth by a routine physical examination. Imperforate anus occurs in about 1 in 5000 births and its cause is unknown. Children who have imperforate anus may also have other congenital anomalies. The acronym VACTERL describes the associated problems that infants with imperforate anus may have: Vertebral defects, Anal atresia, Cardiac anomalies, Tracheoesophageal fistula, Esophageal atresia, Renal anomalies, and Limb anomalies.