What is the appropriate medication regimen to start for an adult with severe Crohn’s disease experiencing 10–15 bowel movements daily?

Immediate Treatment for Severe Crohn's Disease

For severe Crohn's disease with 10-15 bowel movements daily, start intravenous corticosteroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day) immediately, and simultaneously initiate infliximab 5 mg/kg at weeks 0,2, and 6 as definitive therapy. 1

Initial Assessment and Severity Classification

Your symptom burden of 10-15 bowel movements daily clearly meets criteria for severe disease activity, requiring urgent intervention beyond oral medications. 1

Before starting treatment, confirm:

• Rule out infectious complications (C. difficile, CMV, bacterial overgrowth) as these can mimic severe flares 1
• Exclude abscess or stricture as the cause of symptoms, since biologics should be avoided in obstructive disease 1
• Document baseline inflammatory markers (CRP, fecal calprotectin) and albumin level, as low albumin predicts treatment failure 2

Immediate Induction Strategy

Corticosteroids as Bridge Therapy

Start IV methylprednisolone 60 mg/day or hydrocortisone 400 mg/day for rapid symptom control while biologics take effect. 1

• IV steroids are appropriate for severe disease and provide faster response than oral formulations 1
• Add IV metronidazole concomitantly, as distinguishing active inflammation from septic complications can be difficult in severe disease 1
• Begin tapering once symptoms improve to grade ≤1, typically over 8 weeks total (not 12 weeks, as rapid reduction increases relapse risk) 1, 3

Critical pitfall: Do not continue steroids beyond 8 weeks or use them for maintenance—they are ineffective for long-term control and carry significant toxicity. 1, 3, 4

Definitive Biologic Therapy

Infliximab 5 mg/kg IV at weeks 0,2, and 6 is the definitive treatment with Grade A evidence for severe Crohn's disease. 1, 4

• This is superior to waiting for oral immunomodulators (azathioprine/mercaptopurine), which take 3-6 months to work and have very low certainty evidence 1
• Do not use 5-ASAs (mesalamine, sulfasalazine)—they have no proven benefit in moderate-to-severe Crohn's disease and will only delay appropriate therapy 1, 4
• Consider accelerated infliximab dosing (three doses within 24 days rather than standard 6-week induction) if you have access, as this reduces early colectomy rates from 40% to 6.7% in severe disease 2

What NOT to Do

Avoid these common mistakes:

• Do not start with oral budesonide or prednisolone—these are for mild-to-moderate disease, not severe presentations like yours 1, 5
• Do not use azathioprine or methotrexate as monotherapy—they are too slow-acting for severe disease and have very uncertain efficacy 1
• Do not add 5-ASAs to failing steroids—this adds zero benefit and delays biologic therapy 4
• Avoid infliximab if you have obstructive symptoms (severe cramping, distension, vomiting), as it should not be used with stricturing disease 1

Monitoring During Induction

• Assess response by week 2-4: If no improvement on IV steroids + infliximab, this represents steroid-refractory disease requiring escalation 4
• Complete the 3-dose infliximab induction even if symptoms improve, then transition to maintenance dosing every 8 weeks 6
• Taper steroids starting at week 2-4 once symptoms improve, reducing by approximately 5-10 mg weekly over 8 weeks total 3

Alternative Considerations

If infliximab is contraindicated or unavailable:

• Risankizumab (IL-23 inhibitor) has strong evidence for moderate-to-severe Crohn's disease with 30-39% endoscopic remission rates 7
• Adalimumab dosing for Crohn's is 160 mg day 1,80 mg day 15, then 40 mg every other week 6

Infection Prophylaxis

Given high-dose steroids plus biologic therapy:

• Start PCP prophylaxis if steroids >30 mg daily expected for >3 weeks 3
• Add proton pump inhibitor for GI protection during corticosteroid use 3
• Screen for latent TB and hepatitis B before starting infliximab 6