What is the treatment for an ulcerative colitis (UC) flare?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 9, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Treatment for an ulcerative colitis (UC) flare typically involves a combination of medications to reduce inflammation and control symptoms, with the most recent and highest quality study suggesting a treat-to-target approach with biomarker-based monitoring and endoscopic assessment (1).

Overview of Treatment

For mild to moderate flares, oral 5-aminosalicylates (5-ASAs) like mesalamine (2.4-4.8g daily), sulfasalazine (2-4g daily), or balsalazide (6.75g daily) are often the first-line treatment, as recommended by the Toronto consensus (1). These can be combined with topical 5-ASAs as suppositories or enemas for distal disease.

Corticosteroids and Biologics

Corticosteroids such as prednisone (40-60mg daily, tapered over 8-12 weeks) or budesonide MMX (9mg daily for 8 weeks) may be added for more severe symptoms. For moderate to severe flares not responding to these treatments, biologics like infliximab (5mg/kg at weeks 0,2, and 6, then every 8 weeks), adalimumab (160mg initially, 80mg at week 2, then 40mg every other week), or vedolizumab (300mg at weeks 0,2, and 6, then every 8 weeks) may be necessary, as suggested by the European evidence-based consensus (1).

Maintenance Therapy

Immunomodulators such as azathioprine (2-2.5mg/kg/day) or 6-mercaptopurine (1-1.5mg/kg/day) are sometimes used as maintenance therapy. During flares, patients should stay hydrated, avoid trigger foods, and consider a low-residue diet temporarily.

Biomarker-Based Monitoring

The AGA suggests a monitoring strategy that combines biomarkers and symptoms, rather than symptoms alone, to inform treatment adjustments (1). Fecal biomarkers (fecal calprotectin or fecal lactoferrin) may be optimal for monitoring and may be particularly useful in patients where biomarkers have historically correlated with endoscopic disease activity.

Key Recommendations

  • For patients with UC in symptomatic remission, the AGA suggests using fecal calprotectin <150 mg/g, normal fecal lactoferrin, or normal CRP to rule out active inflammation and avoid routine endoscopic assessment of disease activity (1).
  • In patients with UC with moderate to severe symptoms suggestive of flare, the AGA suggests using fecal calprotectin >150 mg/g, elevated fecal lactoferrin, or elevated CRP to rule in active inflammation and inform treatment adjustment (1).

From the FDA Drug Label

1.3 Ulcerative Colitis RENFLEXIS is indicated for reducing signs and symptoms, inducing and maintaining clinical remission and mucosal healing, and eliminating corticosteroid use in adult patients with moderately to severely active ulcerative colitis who have had an inadequate response to conventional therapy. 2.3 Ulcerative Colitis The recommended dose of RENFLEXIS is 5 mg/kg given as an intravenous induction regimen at 0,2 and 6 weeks followed by a maintenance regimen of 5 mg/kg every 8 weeks thereafter for the treatment of adult patients with moderately to severely active ulcerative colitis.

The treatment for an ulcerative colitis (UC) flare is infiximab (IV), specifically RENFLEXIS, which is indicated for reducing signs and symptoms, inducing and maintaining clinical remission and mucosal healing, and eliminating corticosteroid use in adult patients with moderately to severely active ulcerative colitis. The recommended dose is 5 mg/kg given as an intravenous induction regimen at 0,2, and 6 weeks, followed by a maintenance regimen of 5 mg/kg every 8 weeks 2.

  • Key points:
    • Indication: Moderately to severely active ulcerative colitis
    • Dose: 5 mg/kg IV induction regimen at 0,2, and 6 weeks, followed by 5 mg/kg every 8 weeks
    • Treatment goal: Reduce signs and symptoms, induce and maintain clinical remission and mucosal healing, and eliminate corticosteroid use

From the Research

Treatment Options for Ulcerative Colitis (UC) Flare

The treatment for an ulcerative colitis (UC) flare depends on the severity of the disease. According to 3, mild-to-moderate UC can be managed with:

  • Aminosalicylates
  • Mesalamine
  • Topical corticosteroids
  • Oral corticosteroids reserved for unresponsive cases

Moderate-to-Severe UC Treatment

For moderate-to-severe UC, treatment generally requires:

  • Oral or intravenous corticosteroids in the short-term
  • Consideration of long-term management options such as:
    • Biologic agents (as initial therapy or in transition from steroids)
    • Thiopurines (as bridging therapy) 3

Severe or Fulminant UC Treatment

Patients with severe or fulminant UC who are recalcitrant to medical therapy or who develop disease complications (such as toxic megacolon) should be considered for colectomy 3.

Role of 5-Aminosalicylic Acid Compounds

5-Aminosalicylic acid (5-ASA) compounds, such as mesalamine, are the first-line therapy for inducing and maintaining clinical remission in patients with mild-to-moderate UC 4, 5, 6.

  • Topical mesalazine or oral and topical mesalazine combined are effective for induction of remission and prevention of relapse 7
  • High-dose oral mesalazine (≥3.3 g/day) is also effective for induction of remission and prevention of relapse 7

Safety and Tolerability

5-ASAs are safe and well tolerated, regardless of regimen 7.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.