MedlinePlus Medical Encyclopedia: Imperforate anus

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Imperforate anus

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Illustrations

Digestive system

Imperforate anus repair - series

Imperforate anus

Alternative names Return to top

Anorectal malformation; Anal atresia

Definition Return to top

Imperforate anus is a congenital absence or obstruction of the anal opening.

Causes, incidence, and risk factors Return to top

Imperforate anus is a malformation of the anorectal region that 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 malformations are caused by abnormal development of the fetus, and many are associated with other birth defects. Imperforate anus is a relatively common congenital malformation that occurs in about 1 out of 5,000 infants.

Symptoms Return to top

absence of anal opening
misplaced anal opening
anal opening very near the vaginal opening in the female
no passage of first stool within 24 to 48 hours after birth
stool passed by way of vagina, base of penis or scrotum, or urethra
abdominal distention

Signs and tests Return to top

A physical examination with check for anal patency in the newborn will show the malformation.

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

Treatment Return to top

The infant should undergo evaluation for other anomalies, especially genital, urinary and spinal. Surgical reconstruction of the anus is required. If the rectum connects with other organs, repair of these organs will also be necessary. A temporary colostomy is often required.

Expectations (prognosis) Return to top

The outcome is usually good with treatment, depending on the exact anatomy of the birth defect. Some affected infants may never develop adequate bowel control, depending on the location of the defect.

Complications Return to top

intestinal obstruction
bowel incontinence or constipation

Calling your health care provider Return to top

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 Return to top

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

Update Date: 10/31/2003

Updated by: Grace Jeon, M.D., General Surgeon, Pasadena, CA. Review provided by VeriMed Healthcare Network.

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