How do you screen for colon cancer?

Answer:
If you are older than 50, it is recommended that you have a colon cancer screening, to detect polyps and early cancers that can be treated before symptoms develop. If you have certain risk factors, you will need to start screening earlier or have screening tests more often. Regular screenings may decrease deaths and prevent suffering caused by colorectal cancer. This type of screening is as effective as breast cancer screening in saving lives.

There are three ways to screen for colon cancer. The first is a stool test (to check for blood). Most medical authorities recommend this be done every 1 to 2 years.

The second method is a sigmoidoscopy exam (a test that uses a flexible small scope to look at the lower part of your colon), recommended every 5 years. Most health care providers recommend that the stool test and the sigmoidoscopy be used together.

The third method is a colonoscopy exam. A colonoscopy is similar to a sigmoidoscopy, but it allows the entire colon to be viewed. The patient usually is mildly sedated during a colonoscopy.

The American Cancer Society makes the following recommendations:

Beginning at age 50, both men and women should follow one of these five screening options:

• Yearly Fecal Occult Blood Test (FOBT) - the multiple-sample type (take-home); if positive results, a colonoscopy is needed
• Flexible sigmoidoscopy every 5 years
• Yearly fecal occult blood test plus sigmoidoscopy every 5 years ( this combination is preferred over either of these two tests alone)
• Double-contrast barium enema every 5 years
• Colonoscopy every 10 years

There is insufficient evidence to determine which screening method is best. The colonoscopy is the most thorough, but it takes longer, requires sedation, is slightly riskier (rarely, the bowel can be perforated), and much more expensive than a sigmoidoscopy.

People with certain digestive diseases (such as ulcerative colitis) or a family history of colon cancer may need earlier and more frequent testing. See stool screening for bowel cancer and stool guaiac test.