1. Colon Cancer -- Information from Healthwise
If your doctor thinks that you may have colorectal cancer, you will need a test, called a colonoscopy, that lets the doctor see the inside of your entire colon and rectum.. Sometimes other tests, such as a barium enema or sigmoidoscopy, are used...
http://www.everettclinic.com/kbase/topic/major/hw198266/descrip.htm

2. Barium Enema - screen for colon cancer -- EMedicineHealth Consumer Information
Most colon cancers are adenocarcinomas tumors that develop from the glands lining the colon s inner wall. These tumors are sometimes referred to as colorectal cancer, reflecting the fact that the rectum, the end portion of the colon, can also be...
http://www.emedicinehealth.com/articles/13703-1.asp

3. Cancer, colon -- Mayo Clinic
Colon cancer is cancer of the large intestine (colon), the lower part of your digestive system. Colon cancer risk reduction involves getting regular screening tests. Rectal cancer is cancer of the last 8 to 10 inches of the colon.
http://www.mayoclinic.com/invoke.cfm?objectid=13D504C5-40A0-40DA-9F61138EEAAE16...