Proctoscopy- Colorectal Medicine

Proctoscopy, also called rigid sigmoidoscopy, is a procedure performed by a gastroenterologist to visually inspect the anus and rectum. The procedure involves the use of a proctoscope, which is a metallic or plastic hollow tube-like device inserted through the anus to widen it. Proctoscopy procedure is commonly performed to assess and diagnose gastrointestinal disorders like rectal bleeding, colon cancer, polyps, and other abnormalities.

What is Proctoscopy? 

Proctoscopy is a medical procedure performed at the hospital or at the gastroenterologist’s office. It aims to visualize the terminal parts of the colon; the anus and rectum, and assess them for abnormalities. 

  • Rectum: This is the last part of the large intestines (colon) just above the anus
  • Anus: The anal opening and the 3-5 cm canal leading to the rectum.
The organs of the digestive system
William Crochet, Public domain, via Wikimedia Commons. Indolences created it on the English Wikipedia. This SVG image was created by Medium69.

Proctoscopy procedure is done using a device called a “proctoscope” or a “rigid sigmoidoscope”. This device is usually metallic or plastic and looks like a handgun with a wide and hollow barrel. This “barrel” is inserted through the anus to widen it and allow direct visualization of the mucosa (inner layer of the intestine). The tip of the proctoscope usually has a light source as well.

Proctoscopy vs Sigmoidoscopy vs Colonoscopy

All these three are methods of visualization of the colon. The only difference between proctoscopy, sigmoidoscopy, and colonoscopy is how far they go up the colon and which parts they illuminate.

  • Proctoscopy: It illuminates the most terminal parts of the colon; the rectum and anus.
  • Sigmoidoscopy: It goes beyond the rectum and illuminates a higher part of the colon called the “sigmoid colon”. This procedure is done with a sigmoidoscope that can reach up to 25 cms beyond your anal opening.
  • Colonoscopy: It is done to visualize your whole colon. The used instrument, called a colonoscope, is flexible and can travel through all your colon to check for abnormalities. It usually has a camera and a light source at its tip.

Sometimes, sigmoidoscopy and proctoscopy are used interchangeably since both allow the visualization of the most terminal parts of the colon and use very similar devices (only with a different length).

Why is Proctoscopy done?

Proctoscopy is usually done by a gastroenterologist or a gastrointestinal surgeon. The reasons why proctoscopy might be done include:

  • Assessment of the cause of rectal bleeding
  • Checking for internal or external hemorrhoids
  • Searching for polyps or abnormal growths
  • Checking for colorectal cancer
  • Assessment of causes of constipation or diarrhea
  • Taking a biopsy from inside the rectum

Can Proctoscopy detect colon cancer?

Proctoscopy can detect colon cancer if it’s located in the rectum or anus, but will miss tumors located higher up in your colon. It only allows the visualization of the most distant part of the colon; the rectum and anal canal, and can hence only detect colon cancer that grows in this part of the large intestines. Proctoscopy is, therefore, not considered an effective screening tool for colon cancer since it does not allow the assessment of other common sites of colon cancer, like the sigmoid colon.

Preparing for Proctoscopy

Your doctor or surgeon will provide some instructions for you to prepare for proctoscopy. The goal is to have a clear rectum before the procedure to allow proper inspection and visualization during proctoscopy.

Depending on your case, you might be asked to stop eating up to 24 hours before your procedures and switch to a liquid-only diet. Some doctors might prescribe laxatives to empty your bowels. Others might ask you to clean your rectum using an enema before you come in for your appointment.

How is Proctoscopy Performed?

After explaining the procedure to you, your doctor will ask you to take your clothes off and wear your robe.

Proctoscopy position can be any one of these:

  • Left lateral position: You will be asked to sleep on your left side, bend your knees and pull them slightly toward your upper body
  • Lithotomy position: You will be sleeping on your back, knees bent, and legs elevated and widely separated (gynecological position).
  • Knee-elbow position: You will stand on the bed on your knees and then bend your body forward and downward toward the bed (like kneeling).

Your doctor will first gently assess your anus with a gloved and lubricated finger (digital rectal examination). After that, the lubricated proctoscope will be inserted. Your doctor will inspect and assess your anus and rectum for abnormalities. If needed, a tissue biopsy might be taken.

The rectoscope might be used to blow some air to inflate your intestines. You might get the feeling that you want to defecate due to anal stimulation.

The examination should take only a few minutes to finish. Once done, the doctor will remove the proctoscope and will ask you to clean yourself. You can change back to your clothes and can go home after discussing the findings with your doctor.

What are the side effects of Proctoscopy?

Proctoscopy is generally a safe and simple endoscopic procedure that doesn’t have many risks or side effects. Rare complications of proctoscopy include:

  • Anal or rectal bleeding: Sometimes, the proctoscope might injure your rectal or anal mucosa and lead to some bleeding. In most cases, the bleeding resolves alone and requires no special care.
  • Infection: Rarely, an injury can lead to bacterial infection which will require antibiotic treatment.
  • Perforation: In very rare occasions, traumatic insertion or manipulation of the rectoscope can lead to the perforation of the rectum.

Is Proctoscopy painful?

Proctoscopy is not painful, however, it might cause some discomfort. In most cases, no anesthesia is used to perform proctoscopy since it does not cause any pain. Some patients, however, might have low pain thresholds or certain diseases (like an anal fissure), which would make proctoscopy painful. In such cases, a local anesthetic might be used before the procedure.



Disclaimer: Please note that Mya Care does not provide medical advice, diagnosis, or treatment. The information provided is not intended to replace the care or advice of a qualified health care professional. The views expressed are personal views of the author and do not necessarily reflect the opinion of Mya Care. Always consult your doctor for all diagnoses, treatments, and cures for any diseases or conditions, as well as before changing your health care regimen. Do not reproduce, copy, reformat, publish, distribute, upload, post, transmit, transfer in any manner or sell any of the materials on this page without the prior written permission from

About the Author:
Dr. Mersad is a medical doctor, author, and editor based in Germany. He's managed to publish several research papers early in his career. He is passionate about spreading medical knowledge. Thus, he spends a big portion of his time writing educational articles for everyone to learn.