What is an Anoscopy?

Anoscopy is a test similar to colonoscopy and sigmoidoscopy, but it limits the examination to the anal area of the body. During the procedure, a gastroenterologist (GI doctor), colorectal surgeon or proctologist will use a lubricated device called an anoscope to view the inside of a patient’s anus and rectum. The device, also known as an anal speculum, is stiff and short, with the diameter of a large stool (3 to 4 inches long)—unlike endoscopes used during sigmoidoscopy and colonoscopy, which are flexible and have length to be guided up the colon. Common conditions diagnosed and treated with anoscopy include hemorrhoids (swollen veins located in the rectum, anus and surrounding areas of skin), anal fissures (tearing of perforation of the anal tissue) and anal cancer.

What Happens During an Anoscopy?

Anoscopy is a minimally invasive procedure, since most of the anus is located on the outside of the body. The test can be done in a doctor’s office and does not require much time or any sedation. When the procedure begins, the patient will be asked to remove his or her undergarments. The doctor needs to access the patient’s anus, which can be done while the patient is squatting down on the exam table, bent over with feet flat on the floor or lying on a table with knees gathered toward to chest. The doctor will insert the anoscope through the anus and into the patient’s rectum. A doctor may also ask the patient to contract his or her anal muscle, as if to have a bowel movement, in order to ease insertion of the anoscope and in order to get a closer view of irregular bumps that might exist along the tissue lining the rectum. Performing this muscle contraction is called “bearing down.”

A light can then we projected through the hollow of the tubular scope while a doctor examines inside. Overall, the test only takes a few minutes, and then the anal speculum will be slowly removed. Generally, the procedure makes patients feel like they want to have a bowel movement, but it does not cause much pain.

What Might a Doctor Find During an Anoscopy?

During an anoscopy procedure, your doctor may detect hemorrhoids, anal fissures, abscesses (pus that collects and forms a cavity in a patient’s body tissue), fistulas (abnormal tissue connections between the rectum, anus and surrounding skin), inflammation and tumors that may or may not be cancerous. Biopsies can be performed on the spot by inserting a surgical tool through the anoscope; this process usually does not result in much pain either. If you have questions or concerns about anoscopy, sigmoidoscopy or other endoscopy procedures of the anus, rectum and lower colon—please call a medical provider today to discuss your options.


Reviewed 12/29/2011 by David M. Nolan, M.D.
Diplomate of the American Board of Internal Medicine, 2011
Currently a Fellow of Gastroenterology, at UCI 2011-2014