The diagnosis 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 incidence of kidney and bladder problems increases with the severity of the imperforate anus, ranging from 5 to 20 percent with low lesions up to 60 to 90 percent with high lesions. While some of these anomalies may be noted on physical examination, others require further diagnostic tests.
Renal ultrasound is done shortly after birth on all infants to evaluate the kidneys.
Chest X-ray, EKG, and cardiac ultrasound may be ordered to evaluate the heart. Other X-rays may be done to evaluate the trachea and esophagus and the spine. Although the diagnosis of imperforate anus can be made by physical examination, it is often difficult to determine whether the infant has a high or low lesion. A plain radiograph of the abdomen can help locate the lesion. Surgical treatment of infants with imperforate anus depends upon the severity of the condition.