Colonoscopic removal of polyps is an important and well-established tool in the prevention of colorectal cancers. However, high polyp recurrence rates after endoscopic resection, with resultant development of interval cancers, remains a problem; this most commonly stems from unrecognised incomplete polyp resection. Thus, a standardised endoscopic technique is needed that will allow endoscopists to consistently achieve a clear margin of resection. The investigators believe the Cap Assisted Resection Margin Assessment (CARMA) technique will address this problem. This novel technique focuses on a standardised assessment of the resection margin after endoscopic polypectomy utilising available standard high-definition video endoscopes with imaging features including narrow band imaging (NBI) and magnification endoscopy.

Patients with colonic polyps will be considered following below criteria

Inclusion Criteria:

- any polypectomy (though only a maximum of two polyps from one individual participant)

Exclusion Criteria:

• polyps less than 10mm which were resected under endoscopic view with a definite > 1mm clear margin
• scar site recurrence polyps
• polyps with endoscopic evidence of invasion
• pedunculated polyps
• pseudopolyps
• participants who will not be available for follow up endoscopy