Colorectal cancer refers to cancer of the colon and the rectum. The colon is the large intestine and the rectum is the low part of the colon. Colorectal cancer is the third most common cancer worldwide and the fourth most common cause of death. It represents 9.4% of all cancers in men and 10.1% of cancers affecting women. In South Africa, colon cancer is ranked as the fifth most common type of cancer.