Endoscopic approach to polyp recognition

Identification and complete resection of colorectal polyps provide a significant mortality benefit from colorectal cancer. With improvements in colonoscopic techniques and advanced endoscopic imaging techniques, polyp detection has taken on greater complexity since the establishment of bowel cancer screening programmes internationally. All endoscopists operating within symptomatic and screening populations should be aware of endoscopic features associated with advanced neoplasia. Chromoendoscopy and advanced imaging techniques, such as narrow spectrum technologies (narrow band imaging, flexible spectral imaging colour enhancement (FICE) and i-Scan digital contrast (iSCAN)), have specific classification systems to support accurate lesion characterisation. This review summarises the evidence in relation to polyp detection, recognition and characterisation as well as the identification of features of invasion. Future areas of interest include optimal management of large polyps, incorporation of a 'detect, resect and discard' strategy for small and diminutive polyps, expected wider use of computer decision support tools (artificial intelligence and deep learning) and the use of fluorescently labelled molecular probes to improve detection and assessment of neoplasia.