What is the initial treatment for colitis?

Initial Treatment for Colitis

The initial treatment for colitis should be a combination of topical mesalazine 1 g/day with oral mesalazine ≥ 2.4 g/day, which is more effective than either treatment alone for controlling inflammation and symptoms. 1

Treatment Approach Based on Disease Type and Severity

Ulcerative Colitis

• For mild to moderate ulcerative colitis, combination therapy with oral mesalazine (2.4-4.8 g/day) plus topical mesalazine (enemas or suppositories) is the recommended first-line treatment 1, 2
• Once-daily dosing with mesalazine is as effective as divided doses and may improve patient adherence 2
• For patients with proctitis, mesalazine 1-g suppository once daily is the preferred initial treatment 2
• Topical mesalazine is more effective than topical corticosteroids and should be preferred for mild to moderate distal/left-sided colitis 1, 2

Crohn's Disease

• For mild ileocolonic Crohn's disease, high dose mesalazine (4 g/daily) may be sufficient initial therapy 3
• For moderate to severe Crohn's disease, or those with mild to moderate ileocolonic CD that has failed to respond to oral mesalazine, oral corticosteroids such as prednisolone 40 mg daily is appropriate 3
• Budesonide 9 mg daily is appropriate for patients with isolated ileo-caecal disease with moderate disease activity 3, 4

Treatment Escalation Algorithm

When Initial Treatment Fails

• If no improvement within 10-14 days or symptoms worsen, consider increasing oral mesalazine dose to 4.8 g/day 2
• Continue treatment for up to 40 days before determining failure, as sustained complete remission may take time 2
• If inadequate response to optimized mesalazine therapy, add oral corticosteroids such as prednisolone 40 mg daily with tapering over 6-8 weeks 2
• Alternatively, consider budesonide MMX 9 mg/day for left-sided disease as it has fewer systemic side effects than conventional steroids 2, 4

Severe Disease Management

• Severe ulcerative colitis should be managed jointly by a gastroenterologist in conjunction with a colorectal surgeon 3
• Intravenous steroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day) are appropriate for patients with severe disease 3
• Hospitalization is required for severe ulcerative colitis, with treatment involving intravenous steroids, fluid and electrolyte replacement, and close monitoring 1

Medication Efficacy and Evidence

• Mesalazine has been demonstrated in randomized controlled trials to induce both clinical response and remission, and maintain clinical remission in patients with mild-to-moderate UC 5
• High-dose mesalazine therapy (4.8 g/day) shows a median time to cessation of rectal bleeding of approximately 9 days compared to 16 days with standard dose (2.4 g/day) 2
• The proportion of patients who maintained remission at Month 6 using mesalazine 2.4 g once daily (84%) was similar to the comparator (82%) 6

Important Considerations and Monitoring

• Always exclude infectious causes before attributing symptoms to IBD flare 1
• Regular monitoring of renal function is recommended for patients on long-term 5-ASA therapy, including eGFR before starting, after 2–3 months, and then annually 2, 6
• Patients should be informed about a 25-30% chance of needing colectomy in severe cases 3
• Lifelong maintenance therapy is generally recommended for all patients, especially those with left-sided or extensive disease 3, 2

Common Pitfalls to Avoid

• Failing to use combination therapy (topical plus oral mesalazine) which is more effective than either treatment alone 1, 2
• Starting with low-dose therapy rather than optimal dosing (4.8 g/day of mesalazine) for active disease 7
• Discontinuing mesalazine too early after achieving remission, as maintenance therapy reduces the risk of relapse 3, 2
• Using corticosteroids for long-term maintenance, which is ineffective and associated with significant side effects 2, 4
• Tapering corticosteroids too rapidly, which is associated with early relapse 3

By following this evidence-based approach to the initial treatment of colitis, clinicians can optimize patient outcomes while minimizing potential adverse effects from medication.