Complete resection rate of polyps: long follow-up study

Interventions: Daily care: All included patients will undergo a colonoscopy. During colonoscopy all polyps will be removed, but per segment only one polyp will be included in the study: the most proximal polyp. Surveillance will be performed at intervals based on the Dutch gastroenterology guidelines (3 or 5 years).
Study purpose: For the most proximal polyp detected, a single tattoo will be placed contralateral to the polypectomy site. During surveillance, location of previous polypectomy will be detected with help of the tattoo. If a residual polyp is detected at this polypectomy-site, this will be treated and tissue sent for histopathology. If no residual tissue is detected, several biopsies will be taken at the polypectomy site and sent for histopathology. Histopathologic evaluation of the residual tissue will be compared with histopathology of the original polyp.
Primary outcome(s): Percentage of incompletely resected polyps with a diameter of 1-4 mm, 5-9 and 10-20 mm (incomplete resection rate = IRR)
Study Design: N/A: single arm study, Open (masking not used), N/A , unknown, Factorial