What is the treatment for diarrhea in ulcerative colitis?

Treatment of Diarrhea in Ulcerative Colitis

The first-line treatment for diarrhea in ulcerative colitis is a combination of topical mesalazine 1 g daily with oral mesalazine 2-4 g daily for mild to moderate disease, which effectively targets the underlying inflammation causing the diarrhea. 1, 2

Treatment Algorithm Based on Disease Extent and Severity

Distal Ulcerative Colitis (Proctitis or Left-Sided Disease)

• Combination therapy with topical mesalazine 1 g daily plus oral mesalazine 2-4 g daily is the most effective first-line approach for controlling diarrhea 2
• Topical corticosteroids should be reserved as second-line therapy for patients intolerant to topical mesalazine 2
• For patients with proximal constipation contributing to diarrhea symptoms, stool bulking agents or laxatives should be added to the treatment regimen 2
• If no improvement occurs with combination therapy, oral prednisolone 40 mg daily should be initiated with gradual tapering over 8 weeks 2

Extensive Ulcerative Colitis

• Oral mesalazine 2-4 g daily or balsalazide 6.75 g daily is effective first-line therapy for mild to moderate disease with diarrhea 2
• Prednisolone 40 mg daily is appropriate when prompt response is required or mesalazine has been unsuccessful 2
• Long-term steroid use should be avoided; patients with chronic active steroid-dependent disease should be treated with azathioprine 1.5-2.5 mg/kg/day or mercaptopurine 0.75-1.5 mg/kg/day 2

Severe Ulcerative Colitis with Diarrhea

• Hospitalization is required with the following approach 2:
  • Intravenous fluid and electrolyte replacement to correct dehydration
  • Intravenous steroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day)
  • Close monitoring with stool charts to track frequency and character of bowel movements
  • Regular laboratory monitoring (CBC, CRP, electrolytes, albumin)
  • Subcutaneous heparin to reduce thromboembolism risk
  • Nutritional support if malnourished

Advanced Therapies for Refractory Diarrhea

• For patients who fail to respond to conventional therapy, infliximab is indicated for reducing signs and symptoms in moderate to severe ulcerative colitis 3
• The recommended dose is 5 mg/kg given as an intravenous induction regimen at 0,2, and 6 weeks followed by maintenance dosing every 8 weeks 3
• Ciclosporin may be effective for severe, steroid-refractory colitis with persistent diarrhea 2

Important Considerations and Pitfalls

• Always exclude infectious causes of diarrhea before attributing symptoms to UC flare and escalating therapy 1
• Proximal constipation can paradoxically worsen diarrhea symptoms in distal UC and should be addressed with appropriate laxatives 2
• Combination therapy (topical plus oral) is more effective than either treatment alone for controlling diarrhea in distal disease 2
• Rapid steroid tapering is associated with early relapse and should be avoided; generally, prednisolone should be tapered over 8 weeks 2
• Adherence to mesalazine therapy is crucial for effectiveness but often suboptimal in clinical practice 4
• Lifelong maintenance therapy is generally recommended for all patients to prevent recurrent diarrhea episodes, especially for those with left-sided or extensive disease 2

Treatment Selection Based on Evidence Quality

5-aminosalicylates remain the first-line therapy for diarrhea in mild-to-moderate UC due to their favorable risk-benefit profile, with the ability to induce endoscopic remission in up to 45% of patients with topical formulations 5. For moderate-to-severe disease without poor prognostic factors, high-dose 5-ASA therapy should be considered before escalating to biologics 5, 6.