What is the recommended therapeutic approach for an adult patient with Crohn’s disease or ulcerative colitis during an acute flare versus chronic maintenance?

IBD Management: Acute Flare vs Chronic Maintenance

For acute flares, initiate intravenous corticosteroids immediately in severe disease and oral corticosteroids or intensified mesalamine in moderate disease, while chronic maintenance requires lifelong aminosalicylate therapy for ulcerative colitis and immunomodulators or biologics for Crohn's disease to prevent relapse.

Acute Flare Management

Ulcerative Colitis - Mild to Moderate Flare

Distal Disease (Proctitis/Left-Sided)

• Start combination therapy with topical mesalazine 1g daily plus oral mesalazine 2-4g daily as first-line treatment, which achieves superior remission rates compared to monotherapy 1, 2
• If topical mesalazine is not tolerated, switch to topical corticosteroids (budesonide suppository 2-4mg or hydrocortisone enema) while continuing oral mesalazine 1, 2
• For inadequate response after 2-4 weeks, add oral prednisolone 40mg daily, then taper gradually over 8 weeks while maintaining topical agents 1, 2

Extensive Disease

• Use oral mesalazine 2-4g daily as first-line therapy 2
• Add oral prednisolone 40mg daily if mesalazine fails, tapering over 8 weeks 1, 2
• Do not switch between different oral 5-ASA formulations if initial therapy fails—this is ineffective 2

Ulcerative Colitis - Severe/Acute Severe Colitis

Immediate Management

• Admit for intravenous methylprednisolone 40-60mg daily (or hydrocortisone 100mg four times daily) as first-line treatment 2, 3
• Provide IV fluid and electrolyte replacement with potassium supplementation ≥60 mmol/day to prevent toxic dilatation 2
• Administer low-molecular-weight heparin for thromboprophylaxis—rectal bleeding is not a contraindication 1, 2
• Monitor daily: stool frequency, vital signs, complete blood count, CRP, albumin, electrolytes 1, 2

Response Assessment & Escalation

• Assess clinical and biochemical response after 3-5 days of IV corticosteroids 2, 3
• Predictors of steroid failure: >8 stools/day OR 3-8 stools/day with CRP >45 mg/L on day 3 2
• If inadequate response by day 3-5, initiate rescue therapy with infliximab 5mg/kg IV at weeks 0,2, and 6 OR ciclosporin 2mg/kg/day IV 2, 4
• Do not continue ineffective corticosteroids beyond day 5-7—this increases morbidity and delays necessary surgery 2

Surgical Indications

• Colectomy indicated for: failure of rescue therapy after 4-7 days, toxic megacolon without improvement after 24-48 hours, perforation, or massive hemorrhage 2
• Approximately 20-30% of acute severe UC patients require colectomy during the same admission 2

Crohn's Disease - Mild to Moderate Flare

Ileal or Ileocolonic Disease

• Start high-dose mesalazine 4g daily as first-line therapy for mild disease 5
• For moderate disease or mesalazine failure, use oral prednisolone 40mg daily, tapering over 8 weeks 5
• Budesonide 9mg daily is an alternative for isolated ileo-caecal disease with moderate activity, though marginally less effective than prednisolone 5

Crohn's Disease - Severe Flare

• Initiate IV hydrocortisone 400mg/day or methylprednisolone 60mg/day 5
• When severe ileitis makes distinguishing active inflammation from septic complications difficult, add concomitant IV metronidazole alongside IV steroids 6, 5
• Otherwise, administer antibiotics only for documented superinfection, intra-abdominal abscesses, or sepsis 6

Critical Pre-Treatment Considerations

Rule Out Infection First

• Obtain stool studies before escalating IBD-directed therapy to distinguish infection from IBD flare 6
• Do not delay corticosteroid treatment while awaiting stool microbiology results when clinical picture strongly suggests IBD flare 1, 2
• Screen for sexually transmitted infections in sexually active patients with proctitis, especially men who have sex with men 2

Chronic Maintenance Therapy

Ulcerative Colitis Maintenance

Standard Maintenance

• Lifelong maintenance therapy is recommended for all patients, especially those with left-sided or extensive disease 1, 2
• Continue oral mesalazine ≥2g daily (optimal dose 2-4g daily) indefinitely to reduce relapse risk and potentially reduce colorectal cancer risk 1, 2
• For distal disease, maintain topical mesalazine (daily preferred; alternate-day dosing acceptable for selected patients) 2

Advanced Therapy Maintenance

• For moderate-to-severe UC requiring biologics, use infliximab, vedolizumab, ustekinumab, tofacitinib, or upadacitinib over no treatment 2
• Combine TNF antagonists with thiopurines or methotrexate rather than using biologic monotherapy—combination therapy is superior 2
• For patients on combination therapy (TNF antagonist + immunomodulator) in corticosteroid-free remission for ≥6 months, do not withdraw the TNF antagonist 2

Alternative Immunomodulators

• Azathioprine 1.5-2.5mg/kg/day or mercaptopurine 0.75-1.5mg/kg/day are effective but reserved as second-line due to potential toxicity 2

Crohn's Disease Maintenance

Immunomodulator Therapy

• Use azathioprine 1.5-2.5mg/kg/day or mercaptopurine 0.75-1.5mg/kg/day as adjunctive therapy and steroid-sparing agents for chronic disease 5
• These agents are moderately effective in high-risk patients but may cause significant adverse effects 7

Biologic Maintenance

• For moderate-to-severe Crohn's disease, advanced therapies including infliximab, vedolizumab, ustekinumab, or JAK inhibitors are indicated 2
• Combine biologics with immunomodulators rather than using monotherapy 2

Important Note on Mesalamine in Crohn's Disease

• Scientific evidence supporting 5-aminosalicylate compounds for maintaining remission in Crohn's disease is poor 7
• Avoid overprescription of mesalamine for Crohn's disease maintenance 8

Common Pitfalls to Avoid

Acute Management Errors

• Do not use topical corticosteroids as first-line therapy for UC—they are less effective than topical mesalazine 1, 2
• Do not routinely administer antibiotics to IBD patients presenting with acute symptoms unless infection is documented 6
• Do not delay rescue therapy in acute severe UC—patients remaining on ineffective corticosteroids beyond day 5 suffer high morbidity 2
• Avoid rapid tapering of steroids—this is linked to early relapse 2

Chronic Management Errors

• Do not use corticosteroids for maintenance therapy—inappropriate for long-term use 8
• Do not use corticosteroids for perianal Crohn's disease or when sepsis is present 8
• Do not delay introduction or underdose azathioprine, 6-mercaptopurine, or methotrexate when indicated 8
• Do not introduce anti-TNF therapy too late in disease progression, but also avoid using it when patients have sepsis or fibrostenotic strictures 8

Specific UC Considerations

• Address proximal constipation with stool-bulking agents or laxatives, as constipation can exacerbate rectal symptoms 1, 2
• Avoid anti-diarrheal medications in severe UC to prevent toxic megacolon 2