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

Anoscopy

What is an anoscopy?

An anoscopy is a procedure that uses a special lighted scope called an anoscope or anal speculum. An anoscope allows your health care provider to view the lining of your lower rectum and anus to check for signs of injury or disease. Your lower rectum is the last few inches of your large intestine. This is where your body stores stool (poop) before it passes out of your body. Your anus is the opening of the rectum to the outside of your body. This is where your digestive tract ends and your stool leaves your body.

A related procedure is called a high-resolution anoscopy. This procedure uses a special magnifying device called a colposcope along with the anoscope to view these areas. A colposcope may detect small changes in your tissues that the anoscope alone may miss.

An anoscopy can help your 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, inflamed 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 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 may include:

  • Blood in your stool or on toilet paper after a bowel movement
  • Itching around your anus
  • Swelling or hard lumps around your anus
  • Discharge from your anus
  • Painful bowel movements
  • Difficulty having or holding a bowel movement

People who have HIV may also need this test as part of an anal cancer screening. This screening is done to help detect and treat precancer (which can turn into cancer) and prevent anal cancer:

  • Your provider may recommend an anoscopy as part of the screening if you are:
    • Under age 35 and have symptoms or signs of anal cancer
  • Your provider may recommend lab screening, along with a high resolution anoscopy if you have symptoms or signs of anal cancer, as part of the screening if you are:
    • A man who has sex with men and are age 35 or older
    • A transgender woman age 35 or older
    • All other people with HIV age 45 or older

What happens during an anoscopy?

An anoscopy may be done in a provider's office or outpatient clinic. The anoscopy procedure only takes a few minutes. If a high-resolution anoscopy is done or tissue samples are taken, the procedure might take longer.

During an anoscopy:

  • You will put on a gown and remove your underwear.
  • You will lie on an exam table. Your provider will ask you to either lie on your side with your knees bent, on your stomach or to bend forward over 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 a digital rectal exam. Sometimes your provider may apply a numbing medicine if you have anal pain.
  • Your provider will then insert a lubricated tube called an anoscope about two inches into your anus.
  • Most 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, they may use a swab or other tool to collect a tissue sample 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 provider might suggest that you avoid putting anything (like medicines and other products) into your anus for 24 hours before the test. This would also include avoiding anal sex. They 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.

After the anoscopy:

You may have some soreness or bleeding for a few days after the procedure. Your provider may encourage you to sit in a warm bath or to use ice or a topical medicine for soreness.

If you had a biopsy, your provider may tell you when to expect your results and if there are any special instructions. These may include:

  • Avoiding strenuous activities or lifting
  • Taking over-the-counter pain relievers
  • Avoiding constipation by drinking water, eating a high-fiber diet, and taking a supplement, if necessary
  • Not putting anything into your anus until bleeding and pain has stopped

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 may confirm or rule out cancer.

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

References

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  2. Cleveland Clinic: Health Library: Treatments & Procedures [Internet]. Cleveland (OH): Cleveland Clinic; c2023.Anoscopy; [reviewed 2023 May 17; cited 2024 Feb 22]; [about 8 screens]. Available from: https://my.clevelandclinic.org/health/treatments/24993-anoscopy
  3. Cleveland Clinic: Health Library: Diseases & Conditions [Internet]. Cleveland (OH): Cleveland Clinic; c2023. Rectal Cancer; [reviewed 2024 Feb 05; cited 2024 Feb 23]; [about 16 screens]. Available from: https://my.clevelandclinic.org/health/diseases/21733-rectal-cancer
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  8. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998-2024. Anal fissure: Symptoms and causes; 2022 Dec 31 [cited 2024 Jan 10]; [about 12 screens]. Available from: https://www.mayoclinic.org/diseases-conditions/anal-fissure/symptoms-causes/syc-20351424
  9. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998-2024.Hemorrhoids; 2023 Aug 25 [cited 2024 Feb 23]; [about 7 screens]. Available from: https://www.mayoclinic.org/diseases-conditions/hemorrhoids/symptoms-causes/syc-20360268
  10. Merck Manual Professional Version [Internet]. Kenilworth (NJ): Merck & Co. Inc.; 2024. How to Do Anoscopy; [updated 2023 Feb; cited 2024 Feb 23]; [about 7 screens]. Available from: https://www.merckmanuals.com/professional/gastrointestinal-disorders/how-to-do-gastrointestinal-procedures/how-to-do-anoscopy
  11. Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co. Inc.; 2024. Overview of the Anus and Rectum; [updated 2023 Jan; cited 2024 Jan 10]; [about 4 screens]. Available from: https://www.merckmanuals.com/home/digestive-disorders/anal-and-rectal-disorders/overview-of-the-anus-and-rectum
  12. Moeckli B, Canner J, Najafian A, Carbunaru S, Cowell N, Atallah C, Paredes E, Chudnovets A, Fang SH. High-resolution anoscopy, is there a benefit in proceeding directly to the operating room? Tech Coloproctol. 2021 Apr;25(4):461-466. doi: 10.1007/s10151-021-02416-9. Epub 2021 Feb 10. [cited 2024 Feb 23]. PMID: 33569753; PMCID: PMC8016767.
  13. Naomi, J. High-resolution anoscopy: Procedure and findings. Semin Colon Rectal Surg [Internet]. 2017 Apr [cited 2024 Mar 5]; 4(28): 75-80. Available from: https://www.sciencedirect.com/science/article/abs/pii/S1043148917300143 doi: 10.1053/j.scrs.2017.04.004
  14. National Cancer Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; NCI Dictionary of Cancer Terms: Anus; [cited 2024 Feb 22]; [about 1 screen]. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/anus
  15. National Cancer Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; NCI Dictionary of Cancer Terms: Rectum; [cited 2024 Feb 22]; [about 1 screen]. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/rectum
  16. 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 2024 Jan 10]; [about 3 screens]. Available from: https://www.niddk.nih.gov/health-information/digestive-diseases/hemorrhoids/diagnosis
  17. National Institutes of Health: Office of AIDS Research [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; HIV Clinical Guidelines Now Recommend High Resolution Anoscopy as Part of Anal Screening Program for People with HIV [updated 2024 Jul 9; cited 2024 Jul 17]; [about 2 screens]. Available from: https://oar.nih.gov/update-clinical-guidelines-high-resolution-anoscopy-anal-cancer-screening

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.