URL of this page: https://medlineplus.gov/lab-tests/anoscopy/

Anoscopy

What is an anoscopy?

An anoscopy is a procedure that uses a small tube called an anoscope to view the lining of your anus and rectum. A related procedure called high resolution anoscopy uses a special magnifying device called a colposcope along with an anoscope to view these areas.

The anus is the opening of the digestive tract where the stool leaves the body. The rectum is a section of the digestive tract located above the anus. It's where stool is held before it exits the body through the anus. An anoscopy can help a health care provider find problems in the anus and rectum, including hemorrhoids, fissures (tears), and abnormal growths.

What is it used for?

An anoscopy is most often used to diagnose:

  • Hemorrhoids, a condition that causes swollen, irritated veins around the anus and lower rectum. They can be inside the anus or on the skin around the anus. Hemorrhoids are usually not serious, but they can cause bleeding and discomfort.
  • Anal fissures, small tears in the lining of the anus
  • Anal polyps, abnormal growths on the lining of the anus
  • Inflammation. The test can help find the cause of unusual redness, swelling, and/or irritation around the anus.
  • Cancer. High resolution anoscopy is often used to look for cancer of the anus or rectum. The procedure can make it easier for your health care provider to find abnormal cells.

Why do I need an anoscopy?

You may need this test if you have symptoms of a problem in your anus or rectum. These include:

  • Blood in your stool or on toilet paper after a bowel movement
  • Itching around the anus
  • Swelling or hard lumps around the anus
  • Painful bowel movements

What happens during an anoscopy?

An anoscopy may be done in a provider's office or outpatient clinic.

During an anoscopy:

  • You will put on a gown and remove your underwear.
  • You will lie on an exam table. You will either lie on your side or kneel on the table with your rear end raised in the air.
  • Your provider will gently insert a gloved, lubricated finger into your anus to check for hemorrhoids, fissures, or other problems. This is known as digital rectal exam.
  • Your provider will then insert a lubricated tube called an anoscope about two inches into your anus.
  • Some anoscopes have a light on the end to give your provider a better view of the anus and lower rectum area.
  • If your provider finds cells that don't look normal, he or she may use a swab or other tool to collect a sample of tissue for testing (biopsy). High resolution anoscopy may be better than regular anoscopy at finding abnormal cells.

During a high resolution anoscopy:

  • Your provider will insert a swab coated with a liquid called acetic acid through the anoscope and into the anus.
  • The anoscope will be removed, but the swab will remain.
  • The acetic acid on the swab will cause abnormal cells to turn white.
  • After a few minutes, your provider will remove the swab and reinsert the anoscope, along with a magnifying instrument called a colposcope.
  • Using the colposcope, your provider will look for any cells that have turned white.
  • If abnormal cells are found, your provider will take a biopsy.

Will I need to do anything to prepare for the test?

You may want to empty your bladder and/or have a bowel movement before the test. This may make the procedure more comfortable. Your health care provider will let you know if there are any special instructions to follow.

Are there any risks to the test?

There is very little risk to having an anoscopy or a high resolution anoscopy. You may have some discomfort during the procedure. You may also feel a little pinch if your provider took a biopsy.

In addition, you may have a little bleeding when the anoscope is pulled out, especially if you have hemorrhoids.

What do the results mean?

Your results may show a problem with your anus or rectum. These may include:

  • Hemorrhoids
  • Anal fissure
  • Anal polyp
  • Infection
  • Cancer. The biopsy results can confirm or rule out cancer.

Depending on the results, your provider may recommend more tests and/or treatment options.

References

  1. Colon and Rectal Surgery Associates [Internet]. Minneapolis: Colon and Rectal Surgery Associates; c2020. High Resolution Anoscopy; [cited 2020 Mar 12]; [about 3 screens]. Available from: http://www.colonrectal.org/services.cfm/sid:7579/High_Resolution_Anoscopy/index.htmls
  2. Harvard Health Publishing: Harvard Medical School [Internet]. Boston: Harvard University; 2010–2020. Anoscopy; 2019 Apr [cited 2020 Mar 12]; [about 4 screens]. Available from: https://www.health.harvard.edu/medical-tests-and-procedures/anoscopy-a-to-z
  3. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2020. Anal fissure: Diagnosis and treatment; 2018 Nov 28 [cited 2020 Mar 12]; [about 4 screens]. Available from: https://www.mayoclinic.org/diseases-conditions/anal-fissure/diagnosis-treatment/drc-20351430
  4. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2020. Anal fissure: Symptoms and causes; 2018 Nov 28 [cited 2020 Mar 12]; [about 4 screens]. Available from: https://www.mayoclinic.org/diseases-conditions/anal-fissure/symptoms-causes/syc-20351424
  5. Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co. Inc.; 2020. Overview of the Anus and Rectum; [updated 2020 Jan; cited 2020 Mar 12]; [about 2 screens]. Available from: https://www.merckmanuals.com/home/digestive-disorders/anal-and-rectal-disorders/overview-of-the-anus-and-rectum
  6. National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Diagnosis of Hemorrhoids; 2016 Oct [cited 2020 Mar 12]; [about 4 screens]. Available from: https://www.niddk.nih.gov/health-information/digestive-diseases/hemorrhoids/diagnosis
  7. OPB [Internet]: Lawrence (MA): OPB Medical; c2020. Understanding Anoscopy: An In-Depth Look at the Procedure; 2018 Oct 4 [cited 2020 Mar 12]; [about 3 screens]. Available from: https://obpmedical.com/understanding-anoscopy
  8. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2020. Department of Surgery: Colorectal Surgery: High Resolution Anoscopy; [cited 2020 Mar 12]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/surgery/specialties/colorectal/procedures/high-resolution-anoscopy.aspx
  9. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2020. Health Encyclopedia: Hemorrhoids; [cited 2020 Mar 12]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=p00374
  10. UF Health: University of Florida Health [Internet]. Gainesville (FL): University of Florida Health; c2020. Anoscopy: Overview; [updated 2020 Mar 12; cited 2020 Mar 12]; [about 2 screens]. Available from: https://ufhealth.org/anoscopy
  11. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2020. Health Information: Sigmoidoscopy (Anoscopy, Protoscopy): How It Is Done; [updated 2019 Aug 21; cited 2020 Mar 12]; [about 6 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/sigmoidoscopy-anoscopy-proctoscopy/hw2215.html#hw2239
  12. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2020. Health Information: Sigmoidoscopy (Anoscopy, Protoscopy): Risks; [updated 2019 Aug 21; cited 2020 Mar 12]; [about 8 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/sigmoidoscopy-anoscopy-proctoscopy/hw2215.html#hw2256
  13. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2020. Health Information: Sigmoidoscopy (Anoscopy, Protoscopy): Results; [updated 2019 Aug 21; cited 2020 Mar 12]; [about 9 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/sigmoidoscopy-anoscopy-proctoscopy/hw2215.html#hw2259
  14. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2020. Health Information: Sigmoidoscopy (Anoscopy, Protoscopy): Test Overview; [updated 2019 Aug 21; cited 2020 Mar 12]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/sigmoidoscopy-anoscopy-proctoscopy/hw2215.html#hw2218
  15. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2020. Health Information: Sigmoidoscopy (Anoscopy, Protoscopy): Why It Is Done; [updated 2019 Aug 21; cited 2020 Mar 12]; [about 4 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/sigmoidoscopy-anoscopy-proctoscopy/hw2215.html#hw2227

The medical information provided is for informational purposes only, and is not to be used as a substitute for professional medical advice, diagnosis or treatment. Please contact your health care provider with questions you may have regarding medical conditions or the interpretation of test results.

In the event of a medical emergency, call 911 immediately.