What is the management approach for ileitis?

Management of Ileitis

Initial treatment of ileitis should be tailored to disease severity: high-dose mesalazine (4g daily) for mild disease, oral prednisolone 40mg daily for moderate-to-severe disease, and consideration of surgery for refractory cases or limited ileal disease. 1, 2, 3

Critical First Step: Establish the Underlying Cause

Before initiating therapy, recognize that ileitis is not synonymous with Crohn's disease—multiple etiologies exist including infectious causes, NSAID-induced inflammation, ischemia, vasculitis, lymphoma, and ulcerative colitis with backwash ileitis. 4, 5, 6

• Perform additional small bowel imaging to differentiate ulcerative colitis with backwash ileitis from Crohn's disease, as this fundamentally changes management. 3
• Consider alternative diagnoses such as bacterial overgrowth, bile salt malabsorption, or fibrotic strictures before attributing symptoms solely to active inflammation. 2, 3
• Obtain stool cultures and multiplex PCR if infectious colitis is suspected, as most infectious forms require antimicrobial therapy rather than immunosuppression. 7

Treatment Algorithm Based on Disease Severity

Mild Ileocolonic Disease

• Start with high-dose mesalazine 4g daily as first-line therapy for mild inflammatory disease. 1, 2, 3
• This approach is appropriate when symptoms are manageable and there are no signs of severe inflammation. 1

Moderate-to-Severe Disease

• Initiate oral prednisolone 40mg daily for patients with moderate-to-severe symptoms or those who failed mesalazine therapy. 1, 2, 3
• Taper prednisolone gradually over 8 weeks according to disease severity and patient response—rapid reduction is associated with early relapse. 1, 2, 3
• Consider budesonide 9mg daily as an alternative for isolated ileo-cecal disease with moderate activity, though it is marginally less effective than prednisolone. 3

Severe Disease

• Administer intravenous steroids (hydrocortisone 400mg/day or methylprednisolone 60mg/day) for severe presentations. 1, 3
• Add concomitant intravenous metronidazole when severe disease is present, as distinguishing active inflammation from septic complications can be difficult. 1

Adjunctive and Steroid-Sparing Therapies

• Add azathioprine 1.5-2.5mg/kg/day or mercaptopurine 0.75-1.5mg/kg/day as adjunctive therapy and for steroid-sparing effects, though slow onset of action prevents use as monotherapy. 1, 3
• Consider elemental or polymeric diets for patients with contraindications to corticosteroids or those preferring to avoid steroids, though these are less effective than corticosteroids. 2, 3
• Reserve metronidazole 10-20mg/kg/day for selected patients with colonic or treatment-resistant disease, or those wishing to avoid steroids, due to potential side effects. 1, 3

Biological Therapy

• Use infliximab 5mg/kg for refractory disease, but avoid in patients with obstructive symptoms. 1, 3
• Infliximab is effective but should be reserved for cases failing conventional therapy. 1

Surgical Intervention

• Consider surgery for patients who have failed medical therapy or as primary therapy in patients with limited ileal or ileo-cecal disease. 1, 2, 3
• Perform staged procedures in acute severe cases requiring surgery, especially in patients taking ≥20mg prednisolone daily for more than 6 weeks or those on anti-TNF agents. 3

Common Pitfalls to Avoid

• Do not rapidly reduce corticosteroids—this consistently leads to early relapse. 2, 3
• Do not assume all terminal ileitis is Crohn's disease—misdiagnosis leads to inappropriate immunosuppression when antimicrobials or other specific therapies are needed. 4, 5, 6
• Do not delay imaging in suspected backwash ileitis—up to 20% of patients with extensive ulcerative colitis have backwash ileitis, which tends to follow a more refractory course. 3
• Do not overlook NSAID-induced ileitis—this is a common cause that resolves with drug discontinuation rather than immunosuppression. 1, 4, 6

Special Populations

For patients with backwash ileitis (continuous extension of inflammation from cecum into terminal ileum), recognize this occurs in up to 20% of extensive colitis cases and requires additional small bowel imaging to exclude Crohn's disease. 3