Anoscopy

An anoscopy is a medical procedure that uses a specialized scope to examine the lining of the anus and lower rectum for signs of injury or disease.

Overview

An anoscopy is a procedure that uses a special lighted scope called an anoscope or anal speculum. This tool 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, where the body stores stool before it passes out of the body through the anus.

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.

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. While usually not serious, 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, or irritation around the anus.
• Cancer: High-resolution anoscopy is often used to look for cancer of the anus or rectum by making 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, including:

• 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 to detect and treat precancerous cells.

What happens during an anoscopy?

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

During an anoscopy:

• You will put on a gown and remove your underwear.
• You will lie on an exam table, typically on your side with knees bent, on your stomach, or bending forward with your rear end raised.
• Your provider will perform a digital rectal exam by inserting a gloved, lubricated finger into your anus to check for problems. Numbing medicine may be applied if you have anal pain.
• The provider will insert the lubricated anoscope about two inches into your anus.
• If abnormal cells are found, your provider may use a swab or tool to collect a tissue sample for a biopsy.

During a high-resolution anoscopy:

• Your provider inserts a swab coated with acetic acid through the anoscope.
• The acetic acid causes abnormal cells to turn white.
• After a few minutes, the provider reinserts the anoscope along with a colposcope to look for the white-colored cells and perform a biopsy if necessary.

Preparation and Risks

You may want to empty your bladder or have a bowel movement before the test to increase comfort. Your provider may instruct you to avoid putting anything into your anus, including medicines or engaging in anal sex, for 24 hours prior to the test.

Risks are minimal, though you may experience discomfort or a slight pinch if a biopsy is taken. You may notice minor bleeding when the anoscope is removed, especially if you have hemorrhoids. After the procedure, you may experience soreness or bleeding for a few days; your provider may suggest warm baths, ice, or topical medicines for relief.