The term "colon cancer" means any cancer in the colon (large intestine), from the beginning of the colon (cecum) to the end of the colon. Colon cancer, colorectal cancer and rectal cancer are all the same disease. Sometimes the treatment for rectal cancer differs because of its location.

The colon and the rectum together form the lower part of the intestinal tract. Other names for the colon and rectum include the large intestine or large bowel. The large intestine is divided into the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum. The rectum is the almost straight, final portion that ends in the anus. The colon and rectum make up about 7 feet of the last part of the intestine.

Colon cancer is a malignant tumor in the lining of the large intestine. It starts with a single cell that mutates and grows into a visible polyp . If a polyp is allowed to remain in the colon it can grow into a cancerous tumor that can invade other organs. Researchers don't really understand exactly how a polyp progresses to cancer, but most polyps take 3-7 years to become cancerous. Prevention of colon cancer means stopping this process by removing the polyp before it becomes cancerous. Even if the polyp is found in the early stage of becoming cancerous, surgery can cure the cancer before it can spread.

You may wish to understand more about the colon and its role in the digestive system , particularly if you are having surgery for colon cancer. Understanding more about how this system works may help you cope with all that is involved in your treatment and side effects.