Colorectal cancer is a very common gastrointestinal cancer. In men, colorectal cancer is second only to lung cancer and prostate cancer, and in women, colorectal cancer is second only to breast cancer. Colorectal cancer is a serious but curable disease if detected and treated early. Therefore, periodic colorectal cancer screening is a necessary job to ensure the health of each of us. In today's modern society, because colorectal cancer is closely related to diet and living activities, the incidence of the disease is increasing.