What is the treatment for colitis?

Treatment for Colitis

For mild to moderate ulcerative colitis, initiate combination therapy with topical mesalazine 1g daily plus oral mesalazine ≥2.4g daily, as this is more effective than either agent alone for controlling inflammation and achieving remission. 1, 2

Initial Treatment Strategy Based on Disease Location

Proctitis (Rectum Only)

• Start with mesalazine 1g suppository once daily as the preferred initial treatment, as suppositories deliver medication more effectively to the rectum and are better tolerated than foam or enemas 2
• Topical mesalazine is superior to topical corticosteroids and should be the preferred topical agent 1, 2
• Combine topical with oral mesalazine ≥2.4g daily for enhanced efficacy, as combination therapy outperforms either treatment alone 1, 2

Left-Sided Colitis (Proctosigmoiditis)

• Initiate mesalazine enemas ≥1g daily combined with oral mesalazine ≥2.4g daily 2
• This combination is more effective than oral aminosalicylates, topical aminosalicylates, or topical steroids used individually 2
• Once-daily dosing is as effective as divided doses and improves adherence 1, 2

Extensive Colitis/Pancolitis

• Begin with oral mesalazine 2-4g daily combined with topical mesalazine enemas 1g daily 1, 3
• Alternative oral aminosalicylates include balsalazide 6.75g daily or olsalazine 1.5-3g daily 1, 3
• Avoid sulfasalazine 2-4g daily as first-line due to higher side effect profile compared to newer aminosalicylates 1, 3

Treatment Escalation Algorithm for Inadequate Response

Step 1: Optimize Aminosalicylate Therapy

• If no improvement within 10-14 days or symptoms worsen, increase oral mesalazine to 4.8g daily 2
• Continue optimized therapy for up to 40 days before declaring treatment failure, as sustained remission may take time 2
• The median time to cessation of rectal bleeding is approximately 9 days with high-dose mesalazine (4.8g/day) versus 16 days with standard dose (2.4g/day) 2

Step 2: Add Corticosteroids

• If inadequate response to optimized mesalazine after 40 days, add oral prednisolone 40mg daily 1, 2
• Taper prednisolone gradually over 6-8 weeks according to patient response 1, 2
• Single daily dosing of prednisolone is as effective as split-dosing and causes less adrenal suppression 2
• Alternative: Consider budesonide MMX 9mg daily for left-sided disease as it has fewer systemic side effects than conventional steroids 2

Step 3: Severe Disease Requiring Hospitalization

• Admit patients with severe extensive colitis for intensive intravenous therapy 3
• Ensure joint management by gastroenterologist and colorectal surgeon 1, 3
• Monitor daily with physical examination for abdominal tenderness, vital signs four times daily, stool charts, and laboratory tests (CBC, CRP, electrolytes, albumin) every 24-48 hours 3
• Provide supportive care including IV fluids, electrolyte replacement, blood transfusion to maintain hemoglobin >10 g/dL, and subcutaneous heparin for thromboembolism prophylaxis 3

Step 4: Steroid-Dependent or Refractory Disease

• For patients requiring two or more corticosteroid courses in the past year or who become steroid-dependent, escalate to immunomodulators or biologics 2
• Immunomodulator options: Azathioprine 1.5-2.5mg/kg/day or mercaptopurine 0.75-1.5mg/kg/day 1, 3
• Biologic option: Infliximab 5mg/kg IV at weeks 0,2, and 6, then every 8 weeks for moderately to severely active ulcerative colitis with inadequate response to conventional therapy 4

Maintenance Therapy

• Lifelong maintenance therapy with mesalazine is generally recommended, especially for left-sided or extensive disease 1, 2, 3
• Aminosalicylates are effective and safe for long-term maintenance 1, 3
• Monitor renal function regularly: eGFR before starting, after 2-3 months, then annually for patients on long-term 5-ASA therapy 2

Critical Pitfalls to Avoid

• Do not use antidiarrheal medications, as they can mask worsening symptoms while allowing underlying inflammation to progress and may predispose to toxic megacolon 3
• Avoid long-term corticosteroid use due to significant side effects; approximately 50% of patients experience short-term adverse events including acne, edema, sleep/mood disturbance, glucose intolerance, and dyspepsia 2
• Screen for latent tuberculosis before initiating infliximab, as serious infections including TB, bacterial sepsis, and invasive fungal infections can occur 4
• Be aware of hepatosplenic T-cell lymphoma (HSTCL) risk in patients receiving TNF blockers with concomitant azathioprine or 6-mercaptopurine, particularly in adolescent and young adult males with Crohn's disease or ulcerative colitis 4
• Treat proximal constipation with stool bulking agents or laxatives, not antidiarrheals 1, 3