Data were collected about caecal intubation rate, bowel preparation, adverse events (serious gastrointestinal, minor gastrointestinal and cardiovascular) and diagnostic yield. Chi-Square test (p:0.01) was performed to analyze data. Results: In Group A colonoscopy was completed in 132 cases (68.3%) and in Group B in 177 cases (93.1%) (p 000.1). In Group A 14 pts (7.2 %) had incomplete examination for a neoplastic stenosis 21 pts. (10.8%) for poor bowel preparation, 18 pts (9.3%) for diverticular strictures and 8 pts (4.1%) for incomplete sedation. In Group B 12 pts ( 6.2%) had incomplete examination for a neoplastic stenosis and 4pts. (2.1%) for poor bowel preparation (p 0001). In Group A 176 pat (91.1%) had comorbid conditions and 124 (64.2%) more than one associated disease; in Group B 85 pts (44.0%) had comorbid conditions ( 0.0001). In Group A 4 patients (2.1%) had serious GI adverse events,106 pts.(59.9%) minor GI adverse events (p 0.001) and 4 pts (2.1%) cardiovascular adverse events. In group B no patients had serious GI adverse event,34 patients (17.6%) minor GI adverse events and 3 pts (1.5%) cardiovascular adverse events. In Group A 114 pts (59.0%) had normal colonoscopy (11.4%) or diverticulosis (47.5 %); in 8 patients with anemia (4.1%) the exam failed for divertucular stenosis; colonoscopy identified a problem that explained the patient’s symptoms in 72 cases only (37.3%). Conclusions: Our study shows a low caecal intubation rate. Failure to complete exams is mainly attributable to severe diverticular disease, but difficulties with bowel preparation and analgesia contribute too. Colonoscopy has a low diagnostic yield also in patients with symptoms. As diverticular stricture, sedation risks and incomplete preparation are major issues in the elderly, CT colonography might be the first line exam in patients with high risk to undergo incomplete colonoscopies.