The EPoS trials will randomize or register more than 27,500 individuals in different European countries to different surveillance colonoscopy intervals to disentangle the most effective and cost-effective surveillance strategy for the population. Subjects will be randomized according to their presenting polyp chracteristics The EPoS I trial randomizes patients with low-risk adenomas into 5 or 10-year surveillance; ; EPoS II randomizes patients with high-risk adenomas into 3 or 5-yearly surveillance ; EPoS III will include patients with serrated polyps in a one-arm study with surveillance after 5 and 10 years. The primary endpoint for all three trials is incidence of colorectal cancer after 10 years of follow-up.