What is the initial treatment for colitis?

Initial Treatment for Colitis

For mild to moderately active colitis, the first-line treatment is a combination of oral mesalazine ≥2.4 g/day plus topical mesalazine 1 g/day, with the topical formulation matching the extent of disease. 1

Treatment Algorithm Based on Disease Extent and Severity

Mild to Moderate Disease

Proctitis (Limited to Rectum)

• First-line: Mesalazine 1g suppositories once daily 1
• Alternative: Mesalazine foam or enemas 1
• If inadequate response: Add oral mesalazine 2-4g daily 1

Left-sided Colitis

• First-line: Combination of oral mesalazine 2-4g daily plus topical mesalazine 1g/day (enema or foam) 2, 1
• Evidence: This combination is more effective than either oral or topical therapy alone 2
• Dosing convenience: Once-daily dosing is as effective as divided doses 2, 3

Extensive Colitis (Pancolitis)

• First-line: Oral mesalazine 2-4g daily plus topical therapy 1
• Alternative: Balsalazide 6.75g daily 1

Moderate to Severe Disease

• If no response to mesalazine: Oral prednisolone 40mg daily with gradual taper over 8 weeks 2, 1
• For severe disease: IV hydrocortisone 400mg/day or methylprednisolone 60mg/day 2, 1
  • Include IV fluid and electrolyte replacement
  • Blood transfusion to maintain hemoglobin >10 g/dl
  • Subcutaneous heparin for thromboembolism prophylaxis

Evidence for Mesalazine Efficacy

Clinical trials have demonstrated that high-dose mesalazine (4.8 g/day) is more effective than lower doses for inducing remission in mild to moderate ulcerative colitis 4. In placebo-controlled trials, mesalazine demonstrated remission rates of 34-41% compared to 13-22% for placebo 4.

The median time to cessation of rectal bleeding was 9 days with 4.8 g/day mesalazine compared to 16 days with 2.4 g/day 2. However, 37-45 days of therapy may be required before sustained complete remission is achieved 2.

When to Escalate Therapy

If symptoms deteriorate, rectal bleeding persists beyond 10-14 days, or sustained relief from all symptoms has not been achieved after 40 days of appropriate mesalazine therapy, additional therapy with oral systemic steroids should be started 2.

Maintenance Therapy

Lifelong maintenance therapy is generally recommended for all patients, especially those with left-sided or extensive disease, and those with distal disease who relapse more than once a year 2, 1. Maintenance therapy with aminosalicylates has been shown to reduce the risk of colorectal cancer 2.

Common Pitfalls to Avoid

1. Inadequate dosing: Starting with too low a dose of mesalazine. Treatment should start at dosages of 4.8 g per day of the active 5-aminosalicylate moiety, rather than starting at a lower dose and increasing if treatment fails 5.

2. Premature discontinuation: Not continuing treatment long enough to achieve remission, as complete remission may take up to 45 days 2.

3. Failure to combine oral and topical therapy: For left-sided colitis, combination therapy is more effective than either approach alone 2, 1.

4. Prolonged steroid use: Using corticosteroids without appropriate steroid-sparing strategies 1.

5. Delayed surgical consultation: For severe colitis, early joint management by gastroenterologist and colorectal surgeon is recommended 2.

Special Considerations

For patients with Crohn's disease colitis, treatment approaches differ slightly:

• In mild ileocolonic Crohn's disease, high-dose mesalazine (4 g/daily) may be sufficient initial therapy 2
• For moderate to severe disease, oral corticosteroids such as prednisolone 40 mg daily is appropriate 2
• Budesonide 9 mg daily is appropriate for patients with isolated ileo-cecal disease 2

For immune checkpoint inhibitor-induced colitis, management differs based on severity grade, with corticosteroids as the primary treatment and consideration of biologics for refractory cases 2.