There is a need for better visualization of polyps during surveillance endoscopy in patients with hereditary colon cancer syndromes like Familial Adenomatous Polyposis (FAP) and Lynch Syndrome (LS), to improve the adenoma detection rate. Optical molecular imaging of adenoma associated biomarkers is a promising technique to accommodate this need. The biomarker Vascular Endothelial Growth Factor (VEGF) is overexpressed in adenomatous colon tissue versus normal tissue and has proven to be a valid target for molecular imaging. The University Medical Center Groningen (UMCG) developed a fluorescent tracer by labeling the VEGF-targeting humanized monoclonal antibody bevacizumab, currently used in anti-cancer therapy, with the fluorescent dye IRDye800CW. The investigators hypothesize that when bevacizumab-IRDye800CW is administered to patients, it accumulates in VEGF expressing adenomas, enabling adenoma visualization using a newly developed near-infrared (NIR) fluorescence endoscopy platform (NL43407.042.13). This hypothesis will be tested in this feasibility study, next to the determination of the optimal tracer dose.