Update on management of non-pedunculated colonic neoplasia

Non-pedunculated colonic neoplasia (NPCN) is increasingly encountered due to expanded bowel cancer screening and improvements in high-definition endoscopy. Flat and sessile lesions carry higher risks of incomplete resection, recurrence and submucosal invasion than pedunculated polyps, making accurate optical diagnosis and appropriate technique selection essential for high-quality care. This review synthesises evidence from 2016 to 2026 providing a contemporary practice-focused update for clinicians delivering endoscopic resection services. Advances in optical characterisation, including Narrow-band imaging International Colorectal Endoscopic classification, Japan NBI Expert Team classification and Kudo pit pattern classifications, have improved real-time prediction of histology and invasion depth, supporting decision-making between cold resection, endomucosal resection (EMR), endoscopic submucosal dissection (ESD) and surgical referral. Cold snare polypectomy and cold EMR have become preferred techniques for small and intermediate lesions due to excellent safety profiles and high complete resection rates. For larger lesions (≥20 mm), piecemeal EMR with systematic margin ablation using snare-tip soft coagulation now represents the standard of care, reducing recurrence to below 10%. Emerging techniques such as underwater EMR, cap-assisted EMR and endoscopic full-thickness resection expand therapeutic options for fibrotic or non-lifting lesions. ESD remains crucial for en bloc resection when superficial submucosal invasion is suspected, though its use varies across the UK and international practice due to differences in training pathways and service configuration. Key knowledge gaps remain, including the role of artificial intelligence-assisted optical diagnosis, comparative effectiveness of advanced resection techniques and the need for standardised global training and quality indicators. Continued evolution of service models, training frameworks and quality assurance will be central to delivering safe, effective and equitable NPCN management.