Colonoscopy is used both diagnostically and therapeutically and permits examination and treatment of the rectum, colon, and a portion of the terminal ileum. Performance of a high-quality colonoscopy examination requires understanding and mastery of cognitive and technical skills.

Preprocedure – Attention must be paid to the general issues of timely scheduling, appropriate patient preparation, targeted history and physical examination, evaluation of bleeding risk, assessment for appropriate sedation, and team pause before commencing sedation. It is also important to understand appropriate indications and recommended surveillance intervals based upon the patient’s risk factors (eg, family history of colorectal cancer, prior adenomatous polyps, hereditary colon cancer syndrome, or inflammatory bowel disease). Finally, obtaining informed consent with a detailed explanation of the risks associated with colonoscopy is essential.

Intraprocedure – Performing a high-quality examination requires careful visualization of the entire colonic mucosa. Metrics such as cecal intubation rates, withdrawal times, and adenoma detection rates serve as surrogate, though imperfect, markers of careful visualization. In addition, a high-quality examination requires appropriate tissue acquisition (eg, surveillance biopsies in inflammatory bowel disease) and endoscopic removal of all polyps less than 2 cm. Removal of polyps larger than 2 cm may require special endoscopic skills.

Postprocedure – There must be immediate, complete, and accurate documentation (both written and photographic) of preparation quality and findings, as well as explicit recommendations for follow-up. Tissue samples taken during colonoscopy must be documented. Pathology results should be reviewed with results and recommendations communicated to the patient and referring providers. Finally, there should be a system for tracking complications.


What happens at a colonoscopy?

During a colonoscopy, the doctor uses a colonoscope, a long, flexible, tubular instrument about 1/2-inch in diameter that transmits an image of the lining of the colon so the doctor can examine it for any abnormalities. The colonoscope is inserted through the rectum and advanced to the other end of the large intestine.

Preparation for colonoscopy

It typically involves the ingestion of a low-residue diet or clear liquids for at least one day prior to the examination, combined with an oral gastrointestinal lavage. Most medications may be continued up to the time of colonoscopy, but management of antiplatelet agents and anticoagulants must take into account the procedure-related risk of bleeding and the risk of thrombosis. Antibiotic prophylaxis is not required for patients undergoing colonoscopy.

Routine colonoscopy

It is performed using a high-definition white-light colonoscope. Multiple accessories are available to aid with diagnostic and therapeutic maneuvers. In addition, options are available to enhance visualization during colonoscopy, although many require specialized equipment and training.


Are you awake during a colonoscopy?

You may be awake during the test and may even be able to speak. You will probably not remember anything. You lie on your left side with your knees drawn up toward your chest. The scope is gently inserted through the anus.

How long will it take to recover from a colonoscopy?

Recovery from a colonoscopy, a procedure that examines your large intestine, usually lasts about a day. To help with healing, be sure to follow any post-procedure instructions. This may include resting, drinking lots of fluids, and not drinking alcohol for the first 24 hours.

How painful is a colonoscopy?

Colonoscopies aren't usually painful because most patients receive a sedative before the procedure starts. The sedative makes you so sleepy that you usually don't feel or remember anything of the procedure.

Do I have to rest after a colonoscopy?

After a colonoscopy, you will need to recover from the effects of the sedation, which usually wear off within 30 minutes, and you may need to rest after your colonoscopy preparations. You may experience some discomfort and mild pain in the abdominal area as air is relieved from the procedure and leaves your colon.