pan as well as in many other Westernizing countries. 1 Most of the disease activity in UC patients is mild to moderate, and 5-aminosalicylic acid (5-ASA) has been the most basic drug administered to mild and moderate UC patients. Multiple studies have demonstrated the efficacy of 5-ASA for preventing relapse as well as inducing remission. 2,3 However, most of patients experience disease relapse, even when they continuously take 5-ASA. Once relapse occurs, patients need to take other medications, such as steroids, other immune modifying drugs or biologics. 4 Therefore, optimizing the use of 5-ASA is needed in order to ensure a better course in UC pa