A colonoscopy is a procedure that lets your health care provider check the inside of your entire colon (large intestine). The procedure is done using a long, flexible tube called a colonoscope. The tube has a light and a tiny camera on one end. It is put in your rectum and moved into your colon. In addition to letting your provider see the inside of your colon, the tube can be used to:
During a colonoscopy, your provider may remove tissue or polyps (abnormal growths) for further examination. He or she may also be able to treat problems that are found.
Colonoscopy can help your provider look for problems in your colon. These include any early signs of cancer, inflamed (red or swollen) tissue, ulcers (open sores) and bleeding.
The ACS recommends that people at average risk* of colorectal cancer start regular screening at age 45. This can be done either with a sensitive test that looks for signs of cancer in a person's stool (a stool-based test), or with an exam that looks at the colon and rectum (a visual exam). These options are listed below. People who are in good health and with a life expectancy of more than 10 years should continue regular colorectal cancer screening through the age of 75.
For people ages 76 through 85, the decision to be screened should be based on a person's preferences, life expectancy, overall health, and prior screening history. People over 85 should no longer get colorectal cancer screening.
For screening, people are considered to be at average risk if they do not have:
Colonoscopy is also used to screen for colon cancer and rectal cancer. Screening involves looking for cancer in individuals who do not have any symptoms of the disease. Colonoscopy can also be used to check the colon after cancer treatment.
A colonoscopy may be used to check and, if needed, treat problems such as:
It may also be used to find the cause of unexplained, chronic (long-term) diarrhea or bleeding in the gastrointestinal (GI) tract.