Evaluation of Efficacy of Mesalamine in the Long-term Prevention of Diverticulitis Flares

Inclusion Criteria: * age ≥ 18 years * both males and females patients * positive history of acute diverticulitis flare during the last year. The patients will be recruited only after the complete clinical remission of diverticulitis flare. * patients who have given their free and informed consent Exclusion Criteria: * complicated diverticulitis(fistulas, stenosis, abscesses and/or bleeding) * ascertained hypersensitivity to the salicylates * any severe pathology that can interfere with the treatment or the clinical or instrumental test of the trial * clinically significant renal or hepatic impairment * esophageal, gastric or duodenal ulcer within 30 days prior to randomisation * patients with active malignancy of any type, or history of a malignancy (patients with a history of malignancies that have been surgically removed and who have no evidence of recurrence for at least five years before study enrollment are also acceptable) * treatment with any investigational drug within the previous 30 days * treatment with lactulose or with any compound that lowering the colonic pH can prevent the release of the active moiety from the tablets * recent history or suspicion of alcohol abuse or drug addiction * patients who become unable to conform to protocol * patients with ascertained pregnancy * previous participation in this study