What is the initial treatment for a patient with 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, 2

Treatment Algorithm Based on Disease Severity and Location

Mild to Moderate Colitis

• For proctitis (distal colitis), start with mesalazine 1-g suppositories once daily as the preferred initial treatment 2
• For left-sided colitis, use aminosalicylate enemas ≥ 1 g/day combined with oral mesalazine ≥ 2.4 g/day 1, 2
• Once-daily dosing with mesalazine is as effective as divided doses and may improve adherence 1, 2
• Start with high-dose oral mesalazine (4.8 g/day) rather than starting at a lower dose, as this leads to faster symptom resolution (median time to cessation of rectal bleeding is approximately 9 days with 4.8 g/day compared to 16 days with 2.4 g/day) 2, 3

Treatment Escalation for Inadequate Response

• 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 4, 2
• Alternatively, consider budesonide MMX 9 mg/day for left-sided disease as it has fewer systemic side effects than conventional steroids 2

Severe Colitis

• Hospitalization is required for severe ulcerative colitis 1
• Administer intravenous steroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day) 4
• Provide fluid and electrolyte replacement 1
• Joint management by a gastroenterologist and colorectal surgeon is essential 4
• Patients should be informed about a 25-30% chance of needing colectomy 4, 1

Specific Considerations for Crohn's Disease Colitis

• In mild ileocolonic Crohn's disease, high dose mesalazine (4 g/daily) may be sufficient initial therapy 4
• For moderate to severe Crohn's disease, or those with mild to moderate disease that has failed to respond to oral mesalazine, oral corticosteroids such as prednisolone 40 mg daily is appropriate 4
• Budesonide 9 mg daily is appropriate for patients with isolated ileo-caecal disease with moderate disease activity 4
• Metronidazole 10–20 mg/kg/day may be considered for selected patients with colonic or treatment resistant disease 4

Important Monitoring and Maintenance

• Always exclude infectious causes before attributing symptoms to IBD flare 1
• Regular monitoring of renal function is recommended for patients on long-term mesalazine therapy 2, 5
• After achieving remission, maintenance therapy with mesalazine should be continued to prevent relapse 1, 2, 6
• Lifelong maintenance therapy is generally recommended, especially for those with left-sided or extensive disease 4, 2
• Prednisolone should be reduced gradually according to severity and patient response, generally over 8 weeks, as more rapid reduction is associated with early relapse 4

Potential Pitfalls and Caveats

• Long-term steroid use should be avoided due to significant side effects 2
• Topical mesalazine is more effective than topical corticosteroids and should be preferred for mild to moderate distal/left-sided colitis 1, 2
• Patients should be monitored for mesalazine-induced acute intolerance syndrome (cramping, abdominal pain, bloody diarrhea, fever, headache, and rash) 5
• Patients with known liver disease should be monitored for signs of worsening liver function while on mesalazine 5
• For patients who fail conventional therapy with mesalazine and corticosteroids, biologics such as infliximab should be considered 3