There was a significantly lower cumulative rate of patients with recurrent subocclusion in the AZA group ( 56 % ) compared with the mesalazine group ( 79 % ; OR 3.34 , 95 % CI 1.67-8 .6 ; P = 0.003 ) , with the number needed to treat in order to prevent 1 subocclusion episode of 3.7 favoring AZA .