The primary aim of the study is to examine the rate of complications, complete polyp resection, and polyp recurrence during 5 years of follow-up. The secondary aim of the study is examine factors that are associated with complications, initial complete resection, and recurrence (these include patient factors, polyp characteristics, procedural characteristics, and endoscopist characteristics). The observational study will allow systematic assessment of patients with greater than 20 mm polyps. The data will compliment data obtained from two randomized trials on large polyp resection. No patient will undergo study specific experimental intervention and all patients will receive standard of care.