What is the initial treatment for colitis?

Initial Treatment for Colitis

For mild to moderate ulcerative colitis, start with combination therapy of topical mesalazine 1 g/day plus oral mesalazine ≥2.4 g/day, which is significantly more effective than either treatment alone for controlling inflammation and achieving remission. 1, 2

Treatment Algorithm Based on Disease Location

Proctitis (Rectal Disease Only)

• First-line: Mesalazine 1 g suppository once daily 1
• Suppositories deliver medication more effectively to the rectum and are better tolerated than foam or enemas 1
• Topical mesalazine is superior to topical corticosteroids and should be preferred 1, 2
• If inadequate response, add oral mesalazine ≥2.4 g/day to the suppository regimen 1

Left-Sided Colitis

• First-line: Mesalazine enema ≥1 g/day combined with oral mesalazine ≥2.4 g/day 1, 2
• This combination is more effective than oral aminosalicylates, topical aminosalicylates, or topical steroids used alone 1
• Once-daily dosing is as effective as divided doses and may improve adherence 1, 2

Extensive Colitis

• First-line: Combination of topical mesalazine (≥1 g/day) plus oral mesalazine (≥2.4 g/day) 1, 2
• Start with full-dose therapy rather than escalating from lower doses 3

Treatment Escalation Strategy

Step 1: Initial Therapy (Days 0-14)

• Begin combination topical mesalazine (≥1 g/day) plus oral mesalazine (≥2.4 g/day) 1, 2
• Combination therapy achieves significantly higher improvement rates within 2 weeks compared to oral-only treatment 4
• Median time to cessation of rectal bleeding is approximately 9 days with high-dose mesalazine 1

Step 2: Dose Optimization (Days 10-14 if no improvement)

• Increase oral mesalazine to 4.8 g/day while continuing topical therapy 1, 5
• High-dose mesalazine (4.8 g/day) stops rectal bleeding in 9 days versus 16 days with standard dose (2.4 g/day) 1
• Continue optimized therapy for up to 40 days before determining treatment failure, as sustained remission may take time 1

Step 3: Add Corticosteroids (If inadequate response after 40 days)

• Add oral prednisolone 40 mg daily with gradual tapering over 6-8 weeks 1, 2
• Single daily dosing is as effective as split-dosing and causes less adrenal suppression 1
• More rapid tapering is associated with early relapse 6, 2
• Alternative: Budesonide MMX 9 mg/day for left-sided disease, which has fewer systemic side effects than conventional steroids 1, 7

Crohn's Colitis Considerations

Mild Ileocolonic Crohn's Disease

• High-dose mesalazine 4 g/daily may be sufficient initial therapy 6
• For moderate to severe disease, oral prednisolone 40 mg daily is appropriate 6

Moderate Ileocecal Crohn's Disease

• Budesonide 9 mg daily is appropriate for isolated ileocecal disease with moderate activity 6
• Budesonide is marginally less effective than prednisolone but has fewer systemic side effects 6

Severe Disease

• Intravenous steroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day) are appropriate 6
• Concomitant intravenous metronidazole is often advisable to distinguish active disease from septic complications 6

Critical Management Principles

Before Starting Treatment

• Always exclude infectious causes before attributing symptoms to inflammatory bowel disease flare 2
• Consider alternative explanations such as bacterial overgrowth, bile salt malabsorption, or fibrotic strictures 6

Severe Colitis Requires Different Approach

• Hospitalization with intravenous steroids, fluid and electrolyte replacement, and close monitoring 2
• Joint management by gastroenterologist and colorectal surgeon is essential 6, 2
• Patients should be informed of 25-30% chance of needing colectomy 6, 2
• Subcutaneous heparin to reduce thromboembolism risk 6
• Nutritional support if malnourished 6

Monitoring Requirements

• Regular monitoring of renal function for patients on long-term 5-ASA therapy: eGFR before starting, after 2-3 months, then annually 1, 5
• Evaluate for lack of symptomatic response within 2 weeks to determine need for treatment modification 7

Common Pitfalls to Avoid

• Don't start with suboptimal doses: Begin with full-dose therapy (oral mesalazine ≥2.4 g/day) rather than escalating from lower doses 3
• Don't use oral therapy alone for distal disease: Combination therapy is significantly more effective than oral-only treatment 1, 4
• Don't taper steroids too rapidly: Gradual reduction over 6-8 weeks prevents early relapse 6, 1
• Don't use budesonide for maintenance: It is ineffective for maintenance therapy and prolonged use causes significant adverse effects 7
• Don't delay treatment escalation: If no improvement after 40 days of optimized mesalazine, add corticosteroids rather than continuing ineffective therapy 1

Maintenance After Remission

• Continue mesalazine maintenance therapy to prevent relapse 1, 2
• Lifelong maintenance is generally recommended, especially for left-sided or extensive disease 6, 2
• Maintenance therapy with aminosalicylates, azathioprine, or mercaptopurine reduces relapse risk 6