What is a Colonoscopy?

A colonoscopy is an examination of the lower intestine, the large intestine or colon. The procedure is performed using a thin, flexible video endoscope that allows your healthcare provider to examine the inside of the intestine. It is typically performed under sedation, so it is not a painful examination. 

A colonoscopy is the best screening test available for colon cancer. For the average person, the American Cancer Society recommends starting a screening program around age 45. If a person has no unusual risk factors and the colonoscopy is normal, he or she may only need a colonoscopy once every 10 years.

However, for a person who has polyps (abnormal growths), or has a close family member with colon cancer, more frequent screenings would be required. Colonoscopies can also be performed at an age earlier than 45.

Why Have a Colonoscopy Done?

A colonoscopy can help your provider look for problems in your colon. These include any early signs of cancer, red or swollen (inflamed) tissue, open sores (ulcers), and bleeding.

A colonoscopy is also used to screen for colorectal cancer. A screening looks for cancer in people who don’t have any symptoms of the disease.

A colonoscopy may be used to check and, if needed, treat things such as:

• Colon polyps
• Tumors
• Ulceration
• Redness or swelling (inflammation)
• Pouches (diverticula) along the colon wall
• Narrowed areas (strictures) of the colon
• Any objects that might be in the colon

A colonoscopy may also be used to determine the cause of unexplained, long-term (chronic) diarrhea or bleeding in the GI (gastrointestinal) tract, as well as to check the colon after cancer treatment.