Colon cancer screening can detect polyps and early cancers. Such screening can find abnormalities that can be treated before cancer develops or spreads. Regular screenings may decrease deaths and prevent pain caused by colorectal cancer.
TOOLS OR TESTS
Several tools may be used, either alone or together, to screen for colon cancer:
The first method is a stool test that checks your bowel movements for blood.
Polyps in the colon and smaller cancers often cause small amounts of bleeding that cannot be seen with the naked eye.
The most common method used is the fecal occult blood test (FOBT). Newer stool tests are called the fecal immunochemical test (FIT) and stool DNA test (sDNA).
The second method is a sigmoidoscopy exam.
This test uses a flexible small scope to look at the lower part of your colon. Because it only looks at the last one-third of the large intestine (colon), it may miss some cancers.
A stool test and sigmoidoscopy should be used together.
The third method is a colonoscopy. A colonoscopy is similar to a sigmoidoscopy, but the entire colon can be viewed. You will usually be mildly sedated during a colonoscopy.
Two other methods may be used:
Double-contrast barium enemy, a special x-ray of the large intestine, which includes the colon and rectum
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George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.