Besides colonoscopy, what other screening methods are there?

The technical names for a virtual colonoscopy are computerized topographic (CT) colonography and magnetic resonance (MR) colonography. These 2 screening procedures are relatively new ways of detecting polyps and cancer. Similar to a conventional colonoscopy, the virtual colonoscopy requires the use of a colon prep the day before the procedure. This cleans the waste from the colon and allows for a clearer view of the colon wall.

At the beginning of the examination, a thin tube is inserted into the rectum to inflate the colon. The patient is then moved through a large imaging machine. The machine then produces a computer-generated, 3-dimensional view of the colon.

This procedure has recently been approved by a number of organizations, including the American Cancer Society, as an accurate way of locating large polyps. However, it may miss some small polyps as well as flat lesions, which are more likely to become cancerous.

This procedure could identify a polyp, but it does not allow the physician to perform a biopsy or remove a growth. If a growth is found, the patient would require a conventional colonoscopy to confirm the initial results and remove the growth.

The virtual colonoscopy is a promising medical development and could be an option for you, but conventional colonoscopy is still the gold standard of care. At this point, it’s unlikely that a virtual colonoscopy would be covered by your insurance. Talk to your physician about which procedure is right for you.

This examination is similar to a colonoscopy. The difference is that a sigmoidoscopy only views the lower colon and the rectum for polyps and cancer. Because the sigmoidoscopy doesn't allow for the examination of the entire colon, it's considered less reliable than a colonoscopy. If a polyp is found during a sigmoidoscopy, a full colonoscopy is recommended to inspect the rest of the colon.

One of the symptoms of colon cancer is blood in the stool. Often the loss of blood is so minimal, it cannot be seen and a test must be performed to detect the blood. To perform a fecal occult (occult means hidden) blood test, a special card is provided by the healthcare provider, a small amount of stool is placed on the card and the card is then returned to the healthcare provider or lab. The sample is then tested for blood that might be hidden. This procedure should be performed yearly for people older than 50 years. If blood is detected, a colonoscopy is recommended to determine the cause of the bleeding.

Barium is a liquid that is put into the colon and rectum using an enema (a tube inserted into the rectum). The barium enables a healthcare provider to see a detailed outline of the colon and rectum in an x-ray. Multiple x-rays are taken to show the outline of the colon and rectum at different angles. From the outlines, a healthcare provider may be able to detect the presence of polyps. This screening method has not been shown to be reliable. When polyps are found, a colonoscopy is normally performed to confirm the results.