The aim of the present study is to confirm the above mentioned results propectively Several centers, worldwide distributed, will be involved. A minimum of 281 patients will be required for the study. This calculation will be based on the assumption that a continuity-corrected chi-square test with a type I error of 0.05 and a type II error of 0.20 will be expected to detect a difference between a 4.3% prevalence of diverticulitis in patients with diverticulosis and 8.6% in DICA I patients.