National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Imperforate anus

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Other Names:
Anal atresia; Anal stenosis; Anorectal Malformations
Imperforate anus is a birth defect where the opening to the anus is missing or blocked. The anus, also known as the rectum, is the opening at the end of the intestines through which stool (bowel movement) leaves the body. Imperforate anus may end in a pouch, be too narrow (stenotic or atresic), or open into part of the urinary system, female or male reproductive system, or other system of body[1] Symptoms may include absence of the first stool within 24 to 48 hours after birth, no anal opening, anal opening in an abnormal place, stool coming out from the vagina, base of penis, scrotum, or urethra, and/or swollen belly. Although the exact cause of imperforate anus is not fully understood, it is believed to be due to the abnormal development of the rectum when the embryo is forming inside the womb. Many forms of imperforate anus occur with other birth defects. Imperforate anus may also be part of a syndrome with multiple birth defects. Treatment may include colostomy and surgery to correct the defect. Prognosis depends on the severity and type of imperforate anus and the severity and type of any other birth defects. [1][2]
Last updated: 11/22/2017

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Ectopic anus
Abnormal anus position
0004397
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
Hypospadias 0000047
X-linked inheritance 0001417
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Last updated: 7/1/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 

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  1. Kaneshiro NK. Imperforate anus. MedlinePlus. May 14, 2017; https://medlineplus.gov/ency/article/001147.htm.
  2. Rosen NG. Pediatric Imperforate Anus. Medscape Reference. August 9, 2016; http://emedicine.medscape.com/article/929904-treatment#d6.