Inflammatory Bowel Disease Treatment Guidelines

Introduction to Treatment

The American Gastroenterological Association recommends that the most effective first-line medications for inflammatory bowel disease (IBD) are aminosalicylates for ulcerative colitis and corticosteroids for moderate to severe Crohn's disease, with immunomodulators and biologics reserved for refractory cases 1, 2, 3

For mild to moderate ulcerative colitis, the European Crohn’s and Colitis Organisation suggests first-line therapy with oral aminosalicylates (mesalazine 2-4g daily, olsalazine 1.5-3g daily, or balsalazide 6.75g daily) as the cornerstone of treatment 1, 4
The American Gastroenterological Association recommends combination therapy with topical mesalazine 1g daily plus oral mesalazine for distal disease (proctitis), as it is more effective than either treatment alone 1, 4
For moderate to severe ulcerative colitis, the American College of Gastroenterology suggests patients who fail to improve on combination therapy should be treated with oral prednisolone 40mg daily, with gradual tapering over 8 weeks 1, 2
The European Crohn’s and Colitis Organisation recommends that patients with severe disease require hospitalization and intensive intravenous therapy, with intravenous steroids (hydrocortisone 400mg/day or methylprednisolone 60mg/day) as the mainstay of treatment 2

For mild ileocolonic Crohn's disease, the American Gastroenterological Association suggests high-dose mesalazine (4g/daily) may be sufficient initial therapy, though it has limited benefit compared to its efficacy in ulcerative colitis 3, 4
The European Crohn’s and Colitis Organisation recommends oral corticosteroids such as prednisolone 40mg daily for moderate to severe disease, and budesonide 9mg daily for isolated ileo-cecal disease with moderate activity 3
For fistulizing Crohn's disease, the American College of Gastroenterology suggests infliximab (5mg/kg at weeks 0, 2, and 6) is effective for patients refractory to other treatments 6

The American Gastroenterological Association recommends azathioprine and mercaptopurine for steroid-dependent disease and maintenance of remission, with typical dosing of azathioprine 1.5-2.5mg/kg/day or mercaptopurine 0.75-1.5mg/kg/day 2, 3
The European Crohn’s and Colitis Organisation suggests infliximab is effective for moderate to severe Crohn's disease and fistulizing disease, with standard dosing of 5mg/kg at weeks 0, 2, and 6, then every 8 weeks 3, 6