Introduction: What Are New Roles of Current Colonoscopy?

The recent advances in endoscopic imaging technologies make great changes in the management of colorectal polyps. These changes include optical histologic diagnosis with high definition colonscopy, new management strategies such as resect and discard or do not resect, and differentiation of depth of submucosal invasion. In this focused review series, these new paradigms in management of colorectal polyps are discussed by three, world famous authors. First, Amit Rastogi explained optical diagnosis of small colorectal polyp with high definition colonoscopy using narrow band imaging. Second, Cesare Hassan explained new paradigms for colonoscopic management of diminutive colorectal polyps: resect and discard or do not resect. In the last, Shinji Tanaka described, in detail, endoscopic assessment of invasive colorectal cancer: slight vs. deep submucosal invasion. These focused review series introduce the new roles of current colonoscopy to readers and will help the readers to know how to use the new imaging technologies and paradigms in clinical practices.