An anal Pap test is a screening test that gives us a sample of cells in the anal canal. These cells are looked at under the microscope to look for changes that could lead to anal cancer. This is very similar to the Pap smears of the cervix in women. It can be done for men and women. The anal Pap test does not test or look for colon or rectal cancer.

An anal Pap test can determine whether you are at risk for diseases such as the human papillomavirus (HPV) or anal cancer.

Human Papillomavirus (HPV) is a common virus that men and women get during skin-to-skin contact including sexual contact. Most people do not know they are infected with the virus because it often does not cause symptoms. More than 50 percent of people who are sexually active have had or currently have an HPV infection. The immune system, which fights off infection and disease, usually rids your body of HPV on its own but certain types of HPV may be difficult to eradicate. There are at least 100 types of HPV. Some types can cause common warts on the hands or feet, but these are not usually spread by sexual activity. Other types are further categorized into high-risk and low-risk types. Low-risk types are the types that have the potential to cause warts or changes in the cells of the skin, mouth or genitals (penis, vagina, cervix and anus). High-risk types have the potential to cause anal, cervical, penile, vulvar or vaginal cancer if they are not caught early. Thankfully, the majority of the time, HPV does not cause any problems.

HPV is the main cause of anal cancer in men and women. About 6,000 new cases of anal cancer are diagnosed in the United States annually. Risk factors for anal cancer include:

  • HIV infection
  • Smoking
  • Having anal sex
  • Having multiple sexual partners

The rates of anal cancer are rising each year, especially in men who have sex with men as well as in men and women with HIV. People with HIV may have a harder time fighting off this infection even if they take anti-retroviral medications. Therefore, it is important that all persons with HIV, regardless of gender or sexual orientation, be tested for HPV infection. An anal Pap test may be helpful in finding changes in the cells of the anus so that anal cancer can be prevented or caught early.

What Happens During an Anal Pap Test?

The Pap test can be done quickly. Your provider will insert a small swab, moistened with water, into your anus and move it in a circular motion to try to sample as much of the anal canal as possible. The swab is then placed in a special liquid and sent to the pathology laboratory where a specialist will examine the cells collected for abnormalities. Most people describe the test as scratchy and a bit uncomfortable but not painful. You may expect an occasional tiny spot of blood with bowel movements for up to 24 hours after the test.

What are the Possible Outcomes of an Anal Pap Test?

Your doctor will contact you once your Pap test results are complete. Keep in mind, the Pap test is not 100 percent accurate. You may have one of the following results:

  • Normal or Benign: The cells collected from the anus are normal and the test should be repeated in 1 to 3 years depending on your risk factors. Ask your provider when it should be repeated.
  • Unsatisfactory or Inadequate: Not enough cells were collected to be able to judge if there are abnormalities or not. The test should be repeated.
  • ASCUS (Atypical Squamous Cells of Undetermined Significance): The cells are not completely normal appearing but may be abnormal. Normal cells can look “atypical” because of inflammation or irritation. Further testing may document the presence and type of HPV infection (low- or high-risk) and whether or not to worry about this type of result. A High Resolution Anoscopy will provide further information. However, you might not need any treatment.
  • LSIL (Low Grade Squamous Intraepithelial Lesions): The cells from your anus are abnormal probably due to HPV infection. LSIL could mean that you have warts or precancerous areas. A High Resolution Anoscopy will provide further information, and you might not need any treatment.
  • HSIL (High Grade Squamous Intraepithelial Lesions): The cells from your anus have changes more worrisome for precancerous areas caused by HPV. A High Resolution Anoscopy will find these areas, biopsy them and treat them. This does not mean you have cancer.
  • Squamous Carcinoma: This is a very rare result. It means that the cells are very abnormal with serious changes that are very suspicious for cancer. You must have a High Resolution Anoscopy immediately.

What Happens During a High Resolution Anoscopy (HRA)?

HRA is a procedure where a clear, thin, round tube called an anoscope is inserted into your anal canal. A wooden Q-tip, soaked in vinegar is inserted through the anoscope and left in the canal for about one minute. The swab is then removed and the anoscope is reinserted to look inside the anal canal with a microscope. Brushing an iodine solution and sometimes more vinegar helps to detect abnormalities. If suspicious areas are found, a biopsy will be taken. You will probably not feel the biopsies, but you may experience a pressure-like sensation. The biopsies will be sent to the pathologist to be looked at under the microscope. This will help determine whether these areas are precancerous or warts that would require further treatment. The procedure can take anywhere from 15 to 45 minutes.

Preparing for High Resolution Anoscopy

One day before the procedure please:

  • Do not have receptive anal sex
  • Do not put any creams or medications into your anus
  • Do not insert toys, fingers or other objects in your anus
  • Do not douche or use enemas