What are the treatment options for Crohn's ileocolitis?

Treatment of Crohn's Ileocolitis

For mild Crohn's ileocolitis, initiate high-dose mesalamine 4 g daily as first-line therapy; for moderate to severe disease or mesalamine failure, use oral prednisolone 40 mg daily tapered over 8 weeks; and for severe presentations, administer intravenous corticosteroids with consideration of biologics for refractory cases. 1, 2

Disease Severity Assessment

Before selecting therapy, assess three critical parameters: disease location (ileal, ileocolonic, or colonic), pattern (inflammatory, stricturing, or fistulating), and activity level. 1 Exclude alternative explanations for symptoms including bacterial overgrowth, bile salt malabsorption, fibrotic strictures, or dysmotility before attributing symptoms to active inflammation. 1, 3

Treatment Algorithm by Disease Severity

Mild Ileocolonic Disease

• High-dose mesalamine 4 g daily is appropriate as initial therapy for mild ileocolonic Crohn's disease. 1, 2, 3
• This directly targets intestinal inflammation rather than merely controlling symptoms. 2
• Mesalamine has limited efficacy in Crohn's disease compared to ulcerative colitis and should only be used for mild presentations. 2

Moderate to Severe Disease

• Oral prednisolone 40 mg daily is the appropriate treatment for moderate to severe ileocolonic Crohn's disease, or for mild to moderate disease that has failed mesalamine therapy. 1, 2, 3
• Taper prednisolone gradually over 8 weeks according to severity and patient response—rapid reduction is associated with early relapse. 1, 2, 3
• For isolated ileo-caecal disease with moderate activity, budesonide 9 mg daily is an alternative, though marginally less effective than prednisolone. 1, 2

Severe Disease

• Intravenous corticosteroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day) are indicated for severe ileocolonic Crohn's disease. 1, 3
• Administer concomitant intravenous metronidazole when distinguishing active inflammation from septic complications is difficult. 1
• Infliximab 5 mg/kg at weeks 0,2, and 6, then every 8 weeks, is appropriate for patients who fail to respond to intravenous corticosteroids or as rescue therapy. 4

Adjunctive and Alternative Therapies

• Azathioprine 1.5-2.5 mg/kg/day or mercaptopurine 0.75-1.5 mg/kg/day serve as steroid-sparing agents and adjunctive therapy for chronic disease. 1, 2
• Elemental or polymeric diets are less effective than corticosteroids but may induce remission in patients with contraindications to steroids or those preferring to avoid them. 1, 3
• Metronidazole 10-20 mg/kg/day is effective but not recommended as first-line therapy due to side effects; reserve for colonic or treatment-resistant disease. 1, 3

Critical Pitfalls to Avoid

• Do not taper corticosteroids rapidly—this significantly increases early relapse rates. 1, 3
• Do not assume persistent symptoms represent active inflammation; bacterial overgrowth, bile salt malabsorption, and fibrotic strictures frequently mimic active disease. 1, 3
• Do not use mesalamine beyond mild disease—it has limited efficacy in moderate to severe Crohn's disease and delays appropriate corticosteroid therapy. 2
• When using infliximab with azathioprine or 6-mercaptopurine, recognize the increased risk of hepatosplenic T-cell lymphoma, particularly in adolescent and young adult males with Crohn's disease. 4

Surgical Considerations

• Surgery should be considered for patients who have failed medical therapy or as primary therapy in patients with limited ileal or ileo-caecal disease. 3
• Some patients with limited disease may benefit from early surgical resection rather than prolonged medical management. 3