Recurrence after endoscopic mucosal resection of laterally spreading lesions (LSL) >= 20mm in size occurs in approximately 20% of cases at surveillance colonoscopy. We aim to evaluate the efficacy of prophylactic adjuvant thermal ablation of the EMR mucosal defect margin in reducing adenoma recurrence following colonic EMR.

Inclusion Criteria:

• Referred for removal of a colonic polyp >= 20mm in size
• Able to give informed consent to involvement in trial

Exclusion Criteria:

• Younger than 18 years of age
• Highly dependant on medical care
• Women who are pregnant or may be pregnant.
• Taken clopidogrel within 7 days
• Taken warfarin within 5 days
• Had full therapeutic dose unfractionated heparin within 6 hours
• Had full therapeutic dose low molecular weight heparin (LMWH) within 12 hours
• Known clotting disorder
• Previous attempt at EMR of the polyp referred for resection
• Polyp located at the ileo-caecal valve, appendiceal orifice
• Fully circumferential polyp
• Incomplete snare resection of the polyp

Patients were blinded to the treatment allocation. The endoscopists performing the index and surveillance procedures were not blinded to the treatment.