Anal Atresia

(Imperforate Anus; Anorectal Malfunction)

Pronounced: AY-nal ah-TRE-zhuh


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 the child to pass stool. Your child may have:

  • An anal opening that is too thin or in the wrong place
  • A thin layer that covers the opening
  • Intestines that aren’t 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. The reason why isn't clear.

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.


If your baby has anal atresia, symptoms may include:

  • No anal opening at birth
  • Anal opening in the wrong place
  • No stool within 24-48 hours after birth
  • Problems feeding
  • Swollen belly

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


You will be asked about your child's symptoms and health history. A physical exam will be done.

Images may be taken. This can be done with:


Most of the time, anal atresia can be fixed. Talk with your child's doctor about the best plan for your child. Your child may need:


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

  • 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.jpg

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Anal atresia can’t be prevented.


Centers for Disease Control and Prevention

Healthy Children—American Academy of Pediatrics


About Kids Health—The Hospital for Sick Children

Health Canada


Anorectal malformations. EBSCO DynaMed Plus website. Available at: Updated February 18, 2017. Accessed July 2, 2018.

Imperforate anus. Cincinnati Children's website. Available at: Updated March 2018. Accessed July 2, 2018.

Gangopadhyay A, Pandey V. Anorectal malformations. J Indian Assoc Pediatr Surg. 2015 Jan-Mar;20(1):10-15. Available at: Accessed July 2, 2018.

Last reviewed May 2018 by Kari Kassir, MD  Last Updated: 7/2/2018