The body is made up of many types of cells. Normally, cells grow, divide, and produce more cells as needed to keep the body healthy and functioning properly. Sometimes, however, the process goes wrong … cells become abnormal and form more cells in an uncontrolled way. These extra cells form a mass of tissue, called a growth or tumor. Tumors can be benign, which means not cancerous, or malignant, which means cancerous.
Cancer of the colon or rectum is called colorectal cancer. The colon and the rectum are part of the large intestine, which is part of the digestive system. Colorectal cancer occurs when tumors form in the lining of the large intestine, also called the large bowel. Colorectal cancer accounts for almost 10 percent of all cancer deaths in the United States. The risk of developing colorectal cancer rises after age 50. It is common in both men and women.
This story first appeared on http://nihseniorhealth.gov