Imperforate Anus

Alternative names:  anorectal malformations; anal atresia

Definition:  A congenital obstruction of the anal opening.

Causes, incidence, and risk factors:  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, or vagina. A condition of stenosis, or 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 congenital defects. Imperforate anus is a relatively common congenital malformation that occurs in about 1 out of 5,000 infants.


  • 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 or urethra
  • abdominal distention
  • vomiting if infant is fed

Signs and tests: A physical examination with check for anal patency in the newborn will show the malformation.
A lower abdominal X-ray may be recommended.

Treatment: Surgical reconstruction of the anus is required. If the rectum connects with other organs, repair of these organs will also be necessary. Often, a colostomy will be done, with later reconstruction of the anus.

Expectations (prognosis): The outcome is good with treatment. Some affected infants may never develop adequate bowel control depending on the location of the defect.


  • intestinal obstruction
  • bowel incontinence

As with any procedure we perform, your child's safety and well-being our #1 priority.  As always, feel free to contact us with any question that you have.  We would be happy to answer it for you.