Proctoscopy vs Anoscopy: What's Involved in These 2 Different Procedures

Proctoscopy vs Anoscopy: What’s Involved in These 2 Different Procedures

Proctoscopy vs Anoscopy

Since you have been having some issues with your lower GI tract, your doctor recommended you to a gastroenterologist who suggested a proctoscopy. When you got a second opinion, another gastroenterologist recommended an anoscopy. What are these procedures, and what is the difference between them?


During a proctoscopy, the doctor uses a proctoscope to examine the structures in the last part of a patient’s colon. These structures include the rectum, the anus and the sigmoid colon. This is the descending colon and is given its name because it has an S-shape. The proctoscope is a rigid instrument and usually has a tiny light bulb at the end that allows the doctor to see into the colon for signs of polyps, anal fissures, abscesses, hemorrhoids, suspicious bleeding or suspected malignancies. Some proctoscopes have a tube that can accommodate other surgical tools that allow the doctor to snip bits of tissue for examination.


When it comes to proctoscopy vs anoscopy, the anoscope is another rigid tool much like the proctoscope. The difference is that the proctoscope is a bit longer than the anoscope. A proctoscope is about 13 centimeters long, while the anoscope is about 10 centimeters long. Because it is shorter, the anoscope is used to examine problems in the anal cavity. These problems include anal fissures, or tears; hemorrhoids, which are dilated veins in the anus or malignancies.

The Procedures

The procedures for proctoscopy vs anoscopy are also a bit different. Here is what happens in both:


Before a proctoscopy, you’ll have a consultation with your doctor, who will take your medical history. You should tell him all of the drugs, medications and even vitamins and nutritional supplements you are taking. The doctor may tell you to stop taking them a few days before you have your procedure, especially those that are anticoagulants.

The day before the test, you will need to clean out your colon through a saline enema. The proctoscopy is most often done at the hospital or a clinic, and it can be done without anesthesia. However, if you are nervous, the doctor can give you a sedative.

You’ll lie on a table in what’s called the Sims’ position. You’ll lie on your left side with your left leg straight and your right leg bent. The doctor first puts on gloves, lubricates a finger and inserts it into your rectum. This is called a digital rectal exam, or DRE. If there are no blockages or painful areas, they then insert the proctoscope.

The doctor may look through a special microscope that helps them see problems in the lower colon more clearly, and the images may be projected onto a screen. They might take a sample of tissue. In some cases, problems such as hemorrhoids are treated at the same time.

The proctoscopy is painless, though you may have a feeling that you want to move your bowels. You may also have some cramping as air is introduced into your lower colon. A proctoscopy takes about 10 minutes, then you can go home.

You may have a bit of bleeding afterwards if you had a biopsy, but it stops after a few days. Your rectum may be a bit uncomfortable and sore for a short while. However, you can return to your usual activities. There are no dietary restrictions after your proctoscopy.

The Anoscopy

As with the proctoscopy, you’ll need to empty your colon before the procedure through an enema. You’ll also need to empty your bladder.

Instead of the Sim’s position, the doctor might have you curl up in a fetal position on the exam table or bend over the table. The doctor will then lubricate the anoscope and insert it into your anus. This exam also differs from the proctoscopy because the doctor may ask you to clench and release your muscles the way you would if you were moving your bowels. This makes it easier for the anoscope to be placed.

The doctor may also perform other exams along with your anoscopy. They may do a DRE to search for any abnormalities or blockages. As with the proctoscopy, the doctor may also take a biopsy if they think there is a suspicious lesion in your anus.

Like the proctoscopy, an anoscopy is painless if not perfectly comfortable. You might feel the urge to move your bowels, and you might feel a pinching sensation if the doctor takes a biopsy. Like the proctoscopy, the anoscopy is a outpatient procedure, so you can go home after the procedure is done.


Anoscopy and proctoscopy are similar procedures, though the anoscopy is a little more limited due to the shorter length of the instrument. Both of them check for abnormal conditions in your anus or rectum, and sometimes the problems can be resolved right away. If a biopsy is taken, the lab will let you and your doctor know what they have found within days. That way, if you have a problem, it can be fixed at an early stage where it is more treatable.

Brian Chandler