Objectives: Adult CF patients have a significantly increased risk of colon adenomatous polyps, yet there is currently no consensus about the optimal screening protocol. The aim of this study is to evaluate the prevalence of colon precancerous abnormalities in CF patient by a systematic colonoscopic screening and surveillance program. Methods: In a cross-sectional design, each individual out of 184 CF patients aged 40+ followed by the Regional CF Centre of Ancona (Marche), Verona (Veneto) and Atri (Abruzzo) is being asked to undergo within the next six months a screening colonoscopy after execution of Fecal Occult Blood Test (FOBT). Assessed outcomes: probability of having at least one polyp, 3+ polyps, one adenoma with severe dysplasia, a colon cancer diagnosis; positive and negative predictive value of FOBT for colonic mucosa lesions. Additional risk factors, such as familiarity for colorectal or breast cancer, IBD and cumulative dose of NSAIDs in the last five years, are being recorded. Results: Until nowadays, 20 patients out of 184 have been evaluated, with 4 positive for polyps (histology in progress). The results of the screening program will be available in the next months. Conclusion: Preliminary data show an increase of potentially evolutionary colonic lesions in CF adults. The precise burden, the optimal screening strategies, the influence of conventional or disease-associated risk factors must be clarified for an effective program. Our study is one of the first pilot experiences to address this aspect