This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations: The following recommendations for post-polypectomy endoscopic surveillance should be applied only after a high quality baseline colonoscopy with complete removal of all detected neoplastic lesions. 1 In the low risk group (patients with 1???2 tubular adenomas?

Main RecommendationsThe following recommendations for post-polypectomy colonoscopic surveillance apply to all patients who had one or more polyps that were completely removed during a high quality baseline colonoscopy. 1 ESGE recommends that patients with complete removal of 1 – 4 < 10 mm adenomas with low grade dysplasia, irrespective of villous components, or any serrated polyp < 10 mm without dysplasia, do not require endoscopic surveillance and should be returned to screening.Strong recommendation, moderate quality evidence.If organized screening is not available, repetition of colonoscopy 10 years after the index procedure is recommended.Strong recommendation, moderate quality evidence. 2 ESGE recommends surveillance colonoscopy after 3 years for patients with complete removal of at least 1 adenoma ≥ 10 mm or with high grade dysplasia, or ≥ 5 adenomas, or any serrated polyp ≥ 10 mm or with dysplasia. Strong recommendation, moderate quality evidence. 3 ESGE recommends a 3 – 6-month early repeat colonoscopy following piecemeal endoscopic resection of polyps ≥ 20 mm.Strong recommendation, moderate quality evidence. A first surveillance colonoscopy 12 months after the repeat colonoscopy is recommended to detect late recurrence.Strong recommendation, high quality evidence. 4 If no polyps requiring surveillance are detected at the first surveillance colonoscopy, ESGE suggests to perform a second surveillance colonoscopy after 5 years. Weak recommendation, low quality evidence.After that, if no polyps requiring surveillance are detected, patients can be returned to screening. 5 ESGE suggests that, if polyps requiring surveillance are detected at first or subsequent surveillance examinations, surveillance colonoscopy may be performed at 3 years. Weak recommendation, low quality evidence.A flowchart showing the recommended surveillance intervals is provided (Fig. 1).

Importance Colorectal cancer is a major health burden. Screening is recommended in many countries. Objective Estimate the effectiveness of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality in a population-based trial. Design Randomized controlled trial in individuals aged 50–64 years. Screening was performed in 1999–2000 (55–64 year age-group) and 2001 (50–54 year age-group). End of follow-up: Dec 31st 2011. Setting Population of Oslo city and Telemark County, Norway. Participants 100,210 individuals were identified in the screening areas. 1,415 individuals were excluded due to prior colorectal cancer, emigration, or death. Three individuals could not be traced in the population registry. Intervention Individuals randomized to the screening group were invited to screening. Within the screening group, individuals were randomized 1:1 to once-only flexible sigmoidoscopy or combination of once-only flexible sigmoidoscopy and fecal occult blood-testing (FOBT). Individuals with positive screening test (cancer, adenoma, polyp ≥10 mm, or positive FOBT) were offered colonoscopy. The control group received no intervention. Main outcome measures Colorectal cancer incidence and mortality. Results 98,792 individuals were included in the intention to screen analyses; 78,220 in the control group and 20,572 in the screening group (10,283 randomized to flexible sigmoidoscopy and 10,289 to flexible sigmoidoscopy and FOBT). Compliance with screening was 63%. After median 10.9 years, 71 individuals had died from colorectal cancer in the screening group, and 330 in the control group (31.4 vs. 43.1 deaths, absolute rate difference 11.7 (95% CI 3.0–20.4) per 100,000 person-years); hazard ratio [HR] 0.73 (95% confidence interval [CI] 0.56–0.94). Colorectal cancer was diagnosed in 253 individuals in the screening group, and 1,086 in the control group (112.6 vs. 141.0 cases, absolute rate difference: 28.4 (95% CI 12.1–44.7) per 100,000 person-years); HR 0.80 (95% CI 0.70–0.92). Colorectal cancer incidence was reduced in both the 50–54 year age-group (HR 0.68; 95% CI 0.49–0.94) and the 55–64 year age-group (HR 0.83; 95% CI 0.71–0.96). There was no difference between the flexible sigmoidoscopy only and the flexible sigmoidoscopy/FOBT screening groups. Conclusion and relevance In Norway, once-only flexible sigmoidoscopy screening or flexible sigmoidoscopy and FOBT reduced colorectal cancer incidence and mortality on a population level compared with no screening. Screening was effective both in the 50–54 and the 55–64 year age-group. Trial registration ClinicalTrials identifier NTC00119912, http://clinicaltrials.gov