Should a patient with a non-flare case of ulcerative colitis (UC) with rectal bleeding be treated with prednisolone or per rectal mesalasine (mesalamine) enema?

Treatment of Non-Flare Ulcerative Colitis with Rectal Bleeding

For a patient with non-flare ulcerative colitis presenting with rectal bleeding, rectal mesalamine enema should be the initial treatment choice, not prednisolone. 1, 2

Clinical Assessment to Guide Treatment Selection

Disease Extent Determines Optimal Therapy

For distal disease (proctitis or proctosigmoiditis):

• Mesalamine suppositories 1g once daily are the preferred first-line treatment for proctitis 1, 2
• Mesalamine enemas ≥1g daily are preferred for proctosigmoiditis extending beyond the rectum 1
• Topical mesalamine is superior to topical corticosteroids for inducing remission 1, 3

For extensive or left-sided disease:

• Combination therapy with oral mesalamine ≥2.4g/day PLUS mesalamine enema 1g daily is superior to either alone 1, 4, 5
• This combination achieves remission in 64% versus 43% with oral therapy alone at 8 weeks 5
• Rectal bleeding ceases significantly faster with combination therapy 4

When to Escalate to Prednisolone

Prednisolone should only be added after optimized mesalamine therapy has failed, specifically: 1

• If rectal bleeding persists beyond 10-14 days despite appropriate mesalamine therapy 1
• If sustained relief from all symptoms has not been achieved after 40 days of appropriate 5-ASA therapy 1
• If the patient is refractory to optimized oral AND rectal mesalamine at maximum doses 1, 2

The typical prednisolone dose when indicated is 40mg daily orally 2

Critical Distinctions: Non-Flare vs. Active Disease

The term "non-flare" with rectal bleeding suggests mild-to-moderate disease activity rather than severe disease. This is crucial because:

• Severe extensive colitis requires hospital admission for intensive treatment 1
• Mild-to-moderate disease should be treated with mesalamine-based therapy first 1, 6
• Systemic corticosteroids are reserved for moderate-to-severe activity or mesalamine failure 1

Evidence Supporting Mesalamine Over Corticosteroids

Mesalamine foam enema demonstrated superiority over prednisolone foam enema in a head-to-head trial: 3

• Clinical remission: 52% with mesalamine versus 31% with prednisolone (p<0.001)
• Significantly more patients had no blood in stools with mesalamine (67% versus 40%, p<0.001)
• Both treatments were well tolerated

Common Pitfalls to Avoid

• Do not use rectal corticosteroids as first-line therapy instead of mesalamine for distal disease 1, 7
• Do not initiate systemic prednisolone without first optimizing mesalamine therapy (both oral and rectal routes at adequate doses) 1
• Do not use rectal suppositories when disease extends beyond the rectum—use enemas instead 1, 2
• Do not forget to address proximal constipation with stool bulking agents or laxatives, which can worsen proctitis 2

Practical Treatment Algorithm

1. Assess disease extent (proctoscopy/sigmoidoscopy with upper disease boundary) 1
2. For proctitis: Start mesalamine suppositories 1g once daily 1, 2
3. For proctosigmoiditis/left-sided disease: Start mesalamine enema 1g daily PLUS oral mesalamine 2.4-4g daily 1
4. For extensive disease: Start combination oral mesalamine ≥2.4g daily PLUS mesalamine enema 1g daily 1, 5
5. Reassess at 10-14 days: If rectal bleeding persists, ensure compliance and consider dose escalation to high-dose oral mesalamine (>3g/day) 1
6. Reassess at 40 days: If no sustained symptom relief, add oral prednisolone 40mg daily 1, 2

The key principle: mesalamine therapy (topical ± oral) is first-line; prednisolone is reserved for mesalamine-refractory disease. 1, 8