After chewing and swallowing, food travels to stomach and small intestine for digestion. After that, most of the nutrients are absorbed in small intestine, and water is absorbed in large intestine together with electrolytes. The food residue becomes stool and passes out through anus. Large intestine is located at abdomen and it consists of rectum, colon, caecum and appendix, it is about 1.5 meters long.
Human body is made up of many different types of cells. Normally, cells grow, divide and produce new cells, so as to keep organs functioning properly and healthily.
Colorectal cancer (CRC) is a result of uncontrolled growth of cells at large intestinal wall. This abnormal growth forms benign polyps at the beginning, after a long period of time, polyps may turns into malignant tumor, i.e. colorectal cancer.