The previously used treatment approach for Crohn disease (CD) was to (1) initiate therapy with 5-aminosalicylate drugs such as mesalamine at diagnosis; (2) begin thiopurine therapy with azathioprine or 6-mercaptopurine if a patient requires repeated courses of glucocorticoids; and (3) begin therapy with anti–tumor necrosis factor (anti-TNF) agents if these other therapies are unsuccessful.