What is the initial treatment for a new case of ulcerative colitis?

Initial Treatment for New-Onset Ulcerative Colitis

For mild to moderate ulcerative colitis, start with 5-aminosalicylic acid (5-ASA) therapy tailored to disease location: rectal 5-ASA 1g daily for proctitis, or oral 5-ASA 2.0-4.8g daily for disease beyond the rectum, with combination oral and rectal therapy offering superior remission rates. 1

Treatment Algorithm Based on Disease Severity and Extent

Mild to Moderate Disease

Ulcerative Proctitis (rectum only):

• First-line: Rectal 5-ASA suppositories 1g daily 1
• Alternative if no response or intolerance: Add oral 5-ASA or switch to topical corticosteroids 1
• Rectal 5-ASA is superior to rectal corticosteroids for inducing remission 1

Left-sided or Extensive Disease:

• First-line: Oral 5-ASA 2.0-4.8g daily 1
• Enhanced efficacy option: Combination of oral 5-ASA plus rectal 5-ASA (enemas ≥1g daily) provides better remission rates than oral therapy alone 1
• Once-daily dosing is acceptable and may improve adherence 1

Reassessment timeline: Evaluate response at 4-8 weeks; if inadequate response, escalate to corticosteroids 1

Moderate to Severe Disease

Oral corticosteroids are first-line therapy for moderate to severe active disease: 1

• Prednisolone 40mg daily is the recommended dose (more effective than 20mg daily, with no additional benefit above 40-60mg daily) 1
• Combine with 5-ASA therapy 1
• Alternative: High-dose 5-ASA alone can be attempted, but if no response within 2 weeks, initiate corticosteroids 1

Critical caveat: Corticosteroids should NEVER be used for maintenance therapy 1

High-Risk or Corticosteroid-Refractory Disease

For patients at high risk of colectomy or those failing corticosteroids within 2 weeks, initiate advanced therapy early rather than continuing step-up approach: 1

Preferred first-line biologic agents (biologic-naïve patients):

• Infliximab or vedolizumab are preferred over adalimumab or golimumab based on network meta-analysis 1
• Standard dosing: Infliximab 5mg/kg IV at weeks 0,2,6, then every 8 weeks 2

Combination therapy consideration:

• Biologic plus immunomodulator (thiopurine) is more effective than monotherapy for achieving corticosteroid-free remission 1
• However, patients with less severe disease who prioritize safety over maximal efficacy may opt for monotherapy 1

Alternative advanced therapies:

• Adalimumab, golimumab, tofacitinib (JAK inhibitor), or ozanimod (S1P modulator) 1, 3

Maintenance Strategy

Continue the same agent that successfully induced remission: 1

• 5-ASA-induced remission: Continue oral 5-ASA ≥2g daily 1
• Biologic-induced remission: Continue the same biologic 1
• Important: Patients in remission on biologics/immunomodulators may discontinue 5-ASA (no added benefit) 1

Common Pitfalls to Avoid

Do not use thiopurine monotherapy for induction (ineffective), though it may be used for maintenance 1

Do not use methotrexate for induction or maintenance in UC (ineffective) 1

Do not switch between different oral 5-ASA formulations if one fails—escalate therapy instead 1

Do not delay advanced therapy in patients with moderate-severe disease at high risk of colectomy, as this increases complications and colectomy risk 1

Treatment Goals

The modern treatment target has shifted from symptom control to achieving complete remission assessed biochemically, endoscopically, and histologically to prevent long-term complications 1. This represents a fundamental change prioritizing mucosal healing over symptomatic improvement alone, which directly impacts long-term morbidity including colectomy risk and colorectal cancer development 3.