What is an imperforate anus?

Imperforate anus is a congenital (present from birth) defect in which the opening to the anus is missing or blocked. Imperforate anus may occur in several forms. The rectum may end in a blind pouch that does not connect with the colon, or it may have openings to the urethra, bladder, the base of penis or scrotum in boys or the vagina in girls. There may also be stenosis (narrowing) or a complete absence of the anus. The problem is caused by abnormal development of the fetus and may be associated with other birth defects. Imperforate anus is a relatively common condition that occurs in about 1 out of 5,000 infants.

Symptoms

• No passage of first stool within 24 to 48 hours after birth

• Stool passes out of the vagina, base of penis, scrotum or urethra

• Swollen belly

Diagnosis

A doctor can diagnose this condition during a physical exam. Imaging tests may be recommended to determine which structures are abnormally connected or absent and to plan for surgical repair.

Treatment

The infant should be checked for other problems, especially those affecting the genitals, urinary tract and spine. Surgical reconstruction of the anus is often needed. If the rectum connects with other organs, repair of these organs will also be necessary through abdominal surgery. A temporary colostomy is often required. When a colostomy is performed, the large intestine is cut and brought to an opening that is made through the wall of the abdomen. This allows bowel contents to empty into a bag. Later, when the repairs to the child’s organs have healed, the colostomy is removed to allow the child to pass normal bowel movements.

Recovery

With treatment, the outcome is usually good. However, it depends on the exact type and severity of the problem. Some infants may never develop adequate bowel control.