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Anal Atresia

  • Cynthia M. Johnson, MA
Publication Type:


Anal Atresia

(Imperforate Anus; Anorectal Malfunction)


Anal atresia is a problem with the way the anus forms and the part of the intestine leading to the anus. It can make it hard or impossible for a child to pass stool (poop). A child may have:

  • An anal opening that is too thin or in the wrong place
  • A thin layer that covers the opening
  • Intestines that are not connected to the anus
  • An unusual link between the intestines and urinary systems that lets stool pass through the urinary system


Anal atresia happens when an unborn baby’s intestines develop the wrong way. It is not known why this happens.

Risk Factors

Anal atresia is more common in boys. It is also more common in those with other health problems, such as Down syndrome and other birth defects.


Problems may be:

  • No anal opening at birth
  • An anal opening in the wrong place
  • No stool within 24 to 48 hours after birth
  • Problems feeding
  • A swollen belly

Mild anal atresia may not be found until later in life. It may show as a lack of bowel control by 3 years of age.


The doctor will ask about your child's symptoms and health history. A physical exam will be done.

Pictures may be taken. This can be done with:


Surgery may be done to fix anal atresia. The type will depend on the defects that the child has. Examples are:

  • Surgery to connect the anus and intestine
  • Anoplasty to move the anus to the correct location
  • Colostomy to attach a part of the intestine to an opening in the wall of the belly to let waste to pass into a bag outside of the body
Temporary Colostomy of an Infant.

exh5756b_97870_1_colostomy infant.jpghttp://services.epnet.com/getimage.aspx?imageiid=74957495exh5756b.jpgexh5756b.jpgNULLjpgexh5756b.jpgNULL\\hgfiler01a\intellect\images\exh5756b.jpgNULL131NULL2008-12-10434414Copyright © Nucleus Medical Media, Inc.


There are no guidelines to prevent anal atresia.





  • Anorectal malformations. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/anorectal-malformations.
  • Anorectal malformations/imperforate anus. Cincinnati Children's website. Available at: https://www.cincinnatichildrens.org/health/a/anorectal-malformations.


  • Kari Kuenn, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.