colon cancer - colon cancer is cancer of the large intestine (colon),the lower part of your digestive system.rectal cancer is cancer of the last 8 to 10 inches of the colon.together,they are often referred to as colorectal cancers,and they make up the second-leading cause of cancer-related deaths in the united states.only ling cancer claims more lives.most cases of colon cancer begins as small,noncancerous (bening)clumps of cells called adenomatous polyps.overtime some of these polyps become cancerous.polyps maybe small and produce few,if any, sypmtoms,so its important to get regular screening test to help prevent colon cancer.if signs and sypmtoms of cancer do appear,they may include a change in bowel habits,blood in your stool, persistent cramping,gas or abdominal pain.despite the relatively high number of cases and deaths,there's good news about colon cancer.screening test,along wityh a few simple changes in your diet and lifestyle,can dramatically reduce your overall risk mof developing colon cancer.