Forty consecutive patients affected by recurrent attacks of symptomatic uncomplicated diverticular disease of the colon were evaluated to investigate the effectiveness of 2 different mesalazine therapeutic schedules in preventing recurrence of the disease. The patients were randomly enrolled and treated with mesalazine 1.6 g/d (group A) or mesalazine 1.6 g/d 10 days per month (group B). Thirty-four patients completed the study (85%): 3 (7.5%, 1 in group A and 2 in group B) were lost to follow-up, 2 (5%, both group B) were withdrawn from the study for protocol violation, and 1 (2.5%) for hospital admission for stroke (group A). Twenty-three patients (67.65%) were symptom free after 24 months of treatment (overall symptomatic score, 0): 14 of 18 in group A (per-protocol, 77.78%; intention to treat, 70% [95% confidence interval [CI], 61.5-91.8]), 9 of 16 in group B (per protocol, 56.25%; intention to treat, 45% [95% CI, 61.5-91.8]; P< 0.05). Four patients (10%) improved, but were not completely symptom free. Six patients (15%) showed recurrence of symptoms: 1 in group A (5.56%) and 5 in group B (31.25%; P < 0.005; overall symptomatic score, 68). Daily mesalazine supplying seems to be more effective than cyclic supplying in maintaining remission in recurrent symptomatic uncomplicated diverticular disease.