Colorectal cancer (CRC) is the second leading cancer disease that leads to death in the United States. According to the American Cancer Society, 49,190 people died of colorectal cancer in 2016. Due to the fact that adenomatous polyps (adenocarcinomas) are very likely to develop into CRC, early and accurate detection of polyps from optical colonoscopy (OC) is important in the prevention and timely treatment of CRC. According to statistics, misdiagnosis rate reaches up to 25% in clinical tests, resulting in low survival rate for patients who suffer colorectal cancer. Thus, automatic detection provided by AI solution is crucial in clinical practice.