ADAM Health Encyclopedia

Imperforate anus

Definition

Imperforate anus is a missing or blocked opening to the anus that is present from birth (congenital).

Alternative Names

Causes

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, base of penis or scrotum in boys, or vagina in girls. A condition of stenosis (narrowing) of the anus or absence of the anus may be present.

The problem is caused by abnormal development of the fetus, and many forms of imperforate anus are associated with other birth defects. It is a relatively common condition that occurs in about 1 out of 5,000 infants.

Symptoms

• Missing or misplaced opening to the anus
• Anal opening very near the vaginal opening in girls
• No passage of first stool within 24 - 48 hours after birth
• Stool passed by way of vagina, base of penis or scrotum, or urethra
• Abdominal distention

Exams and Tests

An imperforate anus can be diagnosed with a physical exam.

A lower abdominal x-ray or contrast enema may be recommended.

Treatment

The infant should be checked for other problems, especially those affecting the genitals, urinary tract, and spine.

Surgical reconstruction of the anus is needed. If the rectum connects with other organs, repair of these organs will also be necessary. A temporary colostomy is often required.

Outlook (Prognosis)

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

Possible Complications

• Intestinal obstruction
• Bowel incontinence or constipation

When to Contact a Medical Professional

This disorder is usually discovered when the newborn infant is first examined. Call your health care provider if a child that was treated for imperforate anus develops abdominal pain, or fails to develop any bowel control by the age of 3.

Prevention

As with most birth defects, there is no known prevention.