What is the initial treatment for colitis?

Initial Treatment of Colitis

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

Treatment Based on Disease Severity

Mild to Moderate Colitis

• For mild to moderate ulcerative colitis, high-dose oral mesalazine (2-3 g/day) is the first-line treatment 2
• Adding topical (rectal) mesalazine to oral therapy is more effective than oral treatment alone 2, 1
• Once-daily dosing with mesalazine is as effective as divided doses and may improve adherence 1
• For patients who fail to respond to initial mesalazine therapy, dose escalation to 4-4.8 g/day orally alongside rectal mesalazine should be considered 2
• Topical mesalazine is more effective than topical corticosteroids for distal/left-sided colitis 1

Moderate to Severe Colitis

• Oral prednisolone 40 mg daily is appropriate for moderate to severe ulcerative colitis or when mesalazine therapy fails 2, 3
• Prednisolone should be reduced gradually over 6-8 weeks; more rapid reduction is associated with early relapse 2, 3
• Budesonide MMX 9 mg daily can be an alternative to conventional steroids in patients with left-sided disease who have inadequate response to 5-ASA 1, 3
• Intravenous steroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day) are appropriate for patients with severe disease requiring hospitalization 2

Special Considerations

Crohn's Colitis

• For mild ileocolonic Crohn's disease, high-dose mesalazine (4 g/daily) may be sufficient initial therapy 2
• For moderate to severe Crohn's disease, oral corticosteroids such as prednisolone 40 mg daily is appropriate 2
• Sulfasalazine 4 g daily is effective for active colonic Crohn's disease but has a higher incidence of side effects compared to mesalazine 2
• Metronidazole (10–20 mg/kg/day) can be considered for selected patients with colonic Crohn's disease or treatment-resistant disease 2

Fistulating and Perianal Disease

• Metronidazole 400 mg three times daily and/or ciprofloxacin 500 mg twice daily are appropriate first-line treatments for simple perianal fistulae 2
• Azathioprine or mercaptopurine may be used for fistulae where distal obstruction and abscess have been excluded 2

Maintenance Therapy

• Lifelong maintenance therapy is generally recommended for all patients, especially those with left-sided or extensive disease 2, 1
• Aminosalicylates are effective for maintaining remission in both ulcerative colitis and Crohn's disease, with efficacy being dose-related (minimum 2 g/day) 4
• Patients who required two or more courses of corticosteroids in the past year, or who become corticosteroid-dependent, require treatment escalation with thiopurines, anti-TNF therapy, vedolizumab, or tofacitinib 2

Monitoring and Safety

• Always exclude infectious causes before attributing symptoms to IBD flare 1, 3
• Patients on long-term 5-ASA therapy should have renal function checked before starting, after 2-3 months, and then annually 2
• Severe colitis should be managed jointly by a gastroenterologist and colorectal surgeon due to a 25-30% chance of needing colectomy 2, 1

Treatment Algorithm

1. Start with combination therapy: oral mesalazine ≥2.4 g/day plus topical mesalazine ≥1 g/day 1
2. If no response after 2-4 weeks, escalate to oral mesalazine 4-4.8 g/day 2
3. If still inadequate response, initiate oral prednisolone 40 mg daily with gradual taper over 6-8 weeks 2, 3
4. For severe disease requiring hospitalization, use intravenous steroids with fluid and electrolyte replacement 2
5. After achieving remission, maintain with appropriate maintenance therapy to prevent relapse 1