• Anal Atresia

    (Imperforate Anus; Anorectal Malfunction)


    Anal atresia is a condition that a baby is born with. It is a problem with the development of the anus and the part of the intestine just over the anus. Anal atresia can make it difficult or impossible for the child to pass stool. The specific problems can vary from person to person but may include:
    • Anal opening is to narrow or in the wrong place
    • Membrane covers the anal opening
    • Intestines are not connected to the anus
    • An abnormal connection between the intestines and urinary systems, allowing stool to pass through urinary system
    Most of the time, anal atresia can be corrected.


    An unborn baby's intestines develop during the fifth to seventh week of pregnancy. A disturbance in this development causes anal atresia. The exact reason for the distubarnces isn't clear.

    Risk Factors

    Anal atresia happens in boys twice as often as girls. It may also occur with other birth defects. The use of steroid inhalers by the mother during pregnancy may be linked to anal atresia.


    If your baby has anal atresia, he/she may have:
    • No anal opening present at birth
    • Anal opening in the wrong location
    • No stool within 24-48 hours after birth
    • Stool being excreted through the vagina, penis, scrotum, or urethra
    • Tight, swollen stomach
    Milder anal atresia may not be apparent until later in life. It may show as a lack of bowel control by age 3.


    Your doctor will ask about your baby's symptoms and medical history. Tests may be done to understand exactly what the problem is. Tests may include the following:
    • Physical examination to determine the presence and location of the anus
    • Abdominal x-ray —type of x-ray that uses radiation to take a picture of structures inside the body
    • MRI—scan that uses magnetic waves to create detailed images of structures inside the body
    • Ultrasound—uses sounds waves to create images of structures inside the body


    Talk with your child's doctor about the best treatment plan for your child. Treatment options include the following:


    Surgery may be an option to correct the anal atresia. The exact surgery will depend on the defects that are present. One type of surgery may help to connect the anus and intestine.
    Another type of surgery is anoplasty. This is done to move the anus to the correct location. It will also make sure that the muscles that control bowel movements are in place.


    A colostomy is done if your baby needs a new way for waste to pass from the body. During this surgery, a part of the intestine is attached to an opening in the wall of the abdomen. Waste can pass out of this opening into a bag outside the body.
    A colostomy may be needed if the birth defect does not allow waste to pass from the body. It may also be done after surgery to the rectum. The colostomy will give the anal area time to heal before waste passes through. The colostomy will be closed once the anus is fully healed.
    Temporary Colostomy of an Infant
    exh5756b 97870 1 colostomy infant.jpg
    Copyright © Nucleus Medical Media, Inc.


    There is no known way to prevent anal atresia.


    National Center on Birth Defects and Developmental Disabilities http://www.cdc.gov/ncbddd/

    US National Library of Medicine http://www.nlm.nih.gov/


    About Kids Health http://www.aboutkidshealth.ca/

    Health Canada http://www.hc-sc.gc.ca/index-eng.php/


    Imperforate anus. Cincinnati Children's Hospital website. Available at: http://www.cincinnatichildrens.org/health/i/imperforate-anus/ . Accessed August 7, 2012.

    Imperforate anus. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Updated June 2012. Accessed August 7, 2012.

    Scott, J, Swenson O. Imperforate anus: results in 63 cases and some anatomical considerations. Tufts University Medical School publication website Available at: http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1613419&blobtype=pdf . Accessed August 7, 2012.

    Revision Information

    • Reviewer: Michael Woods
    • Review Date: 09/2012
    • Update Date: 00/91/2012

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