Colonoscopic detection and removal of polyps is an effective means of reducing the incidence of colorectal cancer. However, removal of all polyps (including all microscopic polyps and small polyps) still has its detrimental effects. Serrated polyps are subdivided into hyperplastic polyps, non-tipped serrated polyps/adenomas, and conventional serrated adenomas, the latter two of which can progress to cancer by some route. Small polyps (6-9 mm) and microscopic polyps (1-5 mm) generally do not carry the characteristics of progressive adenomas compared to larger polyps (≥10 mm). If small polyps and micropolyps can be accurately identified endoscopically, they can be removed and discarded without evaluation by a pathologist. And it has been demonstrated that it is safe and cost-effective to leave benign microproliferative polyps of the sigmoid colon and rectum untreated. Therefore, there is an urgent need for a classification method that can accurately identify all non-tipped serrated polyps/adenomas under colonoscopy and remove them completely.