What is the initial treatment for a patient diagnosed with colitis?

Initial Treatment for Colitis

The first-line treatment for ulcerative colitis is 5-aminosalicylic acid (5-ASA) compounds such as oral mesalazine 2-4g daily or balsalazide 6.75g daily, with treatment approach varying based on disease location and severity. 1

Diagnosis and Assessment

Before initiating treatment, proper diagnosis is essential:

• Endoscopy with biopsy is required for definitive diagnosis of colitis 2
• Flexible sigmoidoscopy with mucosal biopsy is appropriate for initial investigation in acute presentations 2
• Laboratory workup should include:
  • Full blood count, electrolytes, liver and renal function tests
  • C-reactive protein (CRP) and fecal calprotectin
  • Stool cultures to exclude infectious causes including C. difficile 2

Treatment Algorithm Based on Disease Extent and Severity

Mild to Moderate Disease

1. Distal/Proctitis (limited to rectum):

   • First-line: Combination of topical mesalazine 1g daily plus oral mesalazine 2-4g daily 1
   • Topical therapy in the form of suppositories is usually the first choice 2

2. Left-sided Colitis (up to splenic flexure):

   • First-line: Combination of topical mesalazine (enemas) plus oral mesalazine 2-4g daily 1
   • Topical therapy with enemas is appropriate for this extent 2

3. Extensive Colitis (beyond splenic flexure):

   • First-line: Oral mesalazine 2-4g daily or balsalazide 6.75g daily 1
   • Oral therapy is appropriate, often combined with topical therapy 2

Non-response to Initial Therapy

If no response to 5-ASA therapy within 2-4 weeks:

• Add oral prednisolone 40mg daily 1
• Never use corticosteroids for long-term maintenance due to side effects 1

Severe Colitis (Medical Emergency)

For acute severe colitis requiring hospitalization:

• Intravenous steroids (methylprednisolone 60mg/day or hydrocortisone 100mg four times daily) 1, 3
• If no response to IV steroids within 3-5 days, consider rescue therapy with:
  • Infliximab or cyclosporine (equally effective rescue agents) 3
  • Surgical consultation for potential colectomy 2

Maintenance Therapy

After achieving remission:

• All patients should receive maintenance therapy with 5-ASA compounds at ≥2g/day for lifelong use 1
• For frequent relapsers (more than once per year): Consider azathioprine 1.5-2.5mg/kg/day or mercaptopurine 0.75-1.5mg/kg/day 1

Special Considerations

• Infectious colitis must be ruled out before starting immunosuppressive therapy 4
• NSAID use is associated with increased risk of colitis flares and should be avoided 2
• Endoscopic findings of extensive and deep ulcerations are associated with increased risk of colectomy 2
• For strictures in Crohn's disease, endoscopic dilatation may be considered before surgery in selected patients 2

Monitoring Response

• Response to treatment should be determined by a combination of:
  • Clinical parameters (stool frequency, rectal bleeding)
  • Laboratory markers (CRP, fecal calprotectin)
  • Endoscopic evaluation 2
• Mucosal healing should be assessed 3-6 months after treatment initiation 2

Treatment goals have evolved from clinical response to achieving biochemical, endoscopic, and histological remission for better long-term outcomes 1.

Remember that combination therapy (oral + topical 5-ASA) is more effective than either alone for achieving remission in ulcerative colitis 1.