Inflammatory Bowel Disease (IBD) Flare

Acute exacerbation of Crohn's disease or ulcerative colitis

Symptoms / Associated Sx

  • UC: Bloody diarrhea, rectal urgency, tenesmus, crampy lower abdominal pain; systemic signs in severe flare

  • CD: Abdominal pain (often RLQ), diarrhea (may be non-bloody), weight loss, perianal disease, mouth sores

  • Fever, fatigue; extraintestinal: arthritis, uveitis, erythema nodosum, pyoderma gangrenosum, PSC

Denies

  • Recent antibiotics (rules out C. diff as precipitant — always check)

  • Recent NSAID use (NSAIDs precipitate IBD flare)

  • Travel, sick contacts (rules out superimposed infectious colitis)

  • New medications (rules out checkpoint inhibitor colitis, mycophenolate colitis)

Social History (SHx)

Known IBD type (UC vs. CD), extent/severity, current IBD medications and compliance, prior biologics and response, prior IBD surgeries, smoking (worsens CD; paradoxically protective in UC), stress.

Main Etiology (Flare Precipitants)

  • Medication noncompliance (most common); infection (C. diff, CMV); NSAIDs; antibiotics (dysbiosis)

  • Stress, dietary changes; disease progression despite therapy

Most Common DDx

  • C. difficile colitis (always check C. diff PCR before starting steroids in any IBD flare — coexists in 5–10%; treating with steroids alone in undiagnosed C. diff worsens outcome dramatically)

  • CMV colitis (steroid-refractory IBD flare — biopsy for CMV inclusion bodies + tissue PCR; ganciclovir before escalating immunosuppression)

  • Infectious colitis (superimposed bacterial infection; stool cultures; may mimic or precipitate IBD flare)

  • Ischemic colitis (older IBD patient with vascular disease; CT shows watershed thickening; colonoscopy shows ischemic mucosa vs. IBD-pattern)

  • Checkpoint inhibitor colitis (patient on anti-PD1/CTLA4 therapy; may look identical to IBD; treat with steroids; GI + oncology)

  • Irritable bowel syndrome (IBS) (abdominal pain + diarrhea but no blood; normal colonoscopy; fecal calprotectin normal; functional diagnosis — elevated calprotectin rules in IBD)

  • Diverticulitis (LLQ pain + fever in older IBD patient; CT shows pericolonic stranding; colonoscopy 4–6 weeks after)

DATA

  • CBC, CMP, CRP, ESR, albumin; fecal calprotectin; C. diff PCR (mandatory before steroids)

  • Stool cultures; CMV PCR (serum + tissue if steroid-refractory); CT abdomen/pelvis; KUB (toxic megacolon)

  • Colonoscopy/sigmoidoscopy (severity, biopsy for CMV); drug levels (infliximab/adalimumab trough + antibodies)

  • UC severity: Truelove-Witts; Mayo score; CD: Harvey-Bradshaw Index, CDAI

  • Iron studies, B12, folate (Crohn's — malabsorption)

Home Meds

  • Current IBD regimen (5-ASA, azathioprine, 6-MP, MTX, biologics — assess compliance and levels)

  • NSAIDs (hold); antibiotics (identify if recently used); corticosteroids (do not abruptly stop)

Plan

  • Rule out C. diff and infection before starting steroids

  • Mild-Moderate UC: Prednisone 40–60 mg PO daily until response → taper 10 mg/week; mesalamine enemas (Rowasa 4 g PR nightly) for distal disease; mesalamine PO for pan-colitis

  • Severe UC (≥6 bloody stools/day + ≥1 systemic feature):

    • IV methylprednisolone 60 mg daily (or hydrocortisone 300–400 mg/day divided)

    • Day 3 assessment — if no improvement: Cyclosporine 4 mg/kg/day IV continuous OR Infliximab 5 mg/kg IV × 1

    • Surgery consult on admission; Oxford criteria for colectomy prediction

  • Mild-Moderate Crohn's: Budesonide 9 mg PO daily × 8–12 weeks (ileocolonic); prednisone if budesonide insufficient

  • Moderate-Severe Crohn's: IV methylprednisolone 40–60 mg daily; biologic optimization (check trough levels → dose escalate if subtherapeutic; switch class if antibodies); infliximab 5 mg/kg IV at 0/2/6 weeks; adalimumab 160→80→40 mg q2w; vedolizumab or ustekinumab if anti-TNF failure

  • Perianal Crohn's: MRI pelvis; surgery consult (seton, abscess drainage — drain before biologics); Metronidazole 500 mg TID + Cipro 500 mg BID (bridge); infliximab (most evidence)

  • VTE prophylaxis: Enoxaparin 40 mg SQ daily (IBD = high VTE risk)

  • Nutritional support; B12 IM if terminal ileal Crohn's; IV iron if iron deficient

  • Avoid NSAIDs, loperamide (active flare), opioids

  • Daily CBC, CMP, CRP, albumin; trend fever curve; follow C. diff result; biopsy for CMV if steroid-refractory

  • GI consult; surgery consult (severe UC, complicated Crohn's); PT/OT

  • Discharge: Steroid taper (prednisone 10 mg/week); resume/initiate biologic/immunomodulator; VTE prophylaxis education; vaccination (pneumococcus, influenza, HBV — before starting immunosuppression); GI follow-up 1–2 weeks

Red Flags

  • Toxic megacolon (>6 cm + fever + tachycardia + WBC elevation) → NPO, NG tube, IV steroids, surgery urgently

  • No response to IV steroids at Day 3 → rescue therapy (cyclosporine or infliximab) or colectomy

  • Perianal abscess in Crohn's → urgent surgical drainage before starting biologics (risk of sepsis)

  • CMV colitis in steroid-refractory IBD → ganciclovir before further immunosuppression

  • Crohn's + fever + RLQ mass → intra-abdominal abscess → CT + IR drainage + antibiotics (not just steroids)

  • VTE in IBD → IBD confers ~3× VTE risk; anticoagulate promptly

Senior IM Resident Pearls

  • Truelove-Witts severe UC: ≥6 bloody stools/day + at least one of: HR >90, temp >37.8°C, Hgb <10.5, ESR >30 → IV steroids + GI/surgery

  • Oxford criteria at Day 3: Stool frequency >8/day or 3–8/day + CRP >45 → 85% chance of needing colectomy

  • Biologic drug levels: Infliximab/adalimumab trough before escalating — low trough + no antibodies → dose escalate; antibodies → switch; therapeutic + no response → switch class

  • IBD is hypercoagulable — VTE risk 3× baseline; thromboprophylaxis throughout hospitalization

  • Common mistake: Starting steroids without C. diff rule-out — steroids in undiagnosed C. diff dramatically worsens outcomes

  • Common mistake: Starting infliximab with undrained perianal abscess → rapid sepsis; drain first

Labs

Admission Labs

  • CBC with diff

  • CMP

  • BMP

  • CRP

  • ESR

  • Albumin

  • Magnesium

  • Phosphorus

Mandatory Before Steroids

  • C. difficile PCR

  • GI pathogen panel/stool cultures

Additional Labs

  • Fecal calprotectin

  • Blood cultures ×2 (fever/sepsis)

  • CMV PCR (if immunocompromised)

  • Iron studies

  • Ferritin

  • B12

  • Folate

  • Vitamin D

Biologic Workup

  • Infliximab trough level

  • Adalimumab trough level

  • Anti-drug antibodies

Trending Labs

  • CBC daily

  • CMP daily

  • CRP daily

  • Albumin daily

  • ESR every few days

  • Fever curve

Imaging

CT Abdomen/Pelvis with Contrast

Evaluate:

  • Severity

  • Abscess

  • Fistula

  • Obstruction

  • Perforation

KUB

If:

  • Distension

  • Severe flare

  • Concern for toxic megacolon

Evaluate:

  • Colon diameter

Toxic megacolon:

  • Colon >6 cm

Crohn's Perianal Disease

MRI Pelvis

Evaluate:

  • Abscess

  • Fistula

  • Seton planning

Procedures

Flexible Sigmoidoscopy / Colonoscopy

Evaluate:

  • Disease severity

  • Obtain biopsies

  • Rule out CMV

Avoid Full Colonoscopy

If:

  • Toxic megacolon

  • Fulminant colitis

Surgery

Severe UC

  • Surgical consult on admission

Crohn's

If:

  • Abscess

  • Perforation

  • Obstruction

  • Fistula complications

Medications

Ulcerative Colitis

Mild–Moderate

Prednisone

  • 40–60 mg PO daily

Then:

  • Taper by 10 mg/week

Distal Disease

Mesalamine Enema (Rowasa)

  • 4 g PR nightly

Extensive Disease

Mesalamine

  • 2.4–4.8 g PO daily

Severe UC

Methylprednisolone

  • 60 mg IV daily

OR

Hydrocortisone

  • 100 mg IV q6h

Day 3 Nonresponse

Infliximab

  • 5 mg/kg IV x1

OR

Cyclosporine

  • 4 mg/kg/day IV continuous infusion

Crohn's Disease

Mild–Moderate Ileocolonic Disease

Budesonide

  • 9 mg PO daily x8–12 weeks

Moderate–Severe Disease

Methylprednisolone

  • 40–60 mg IV daily

Biologic Therapy

Infliximab

  • 5 mg/kg IV at weeks 0, 2, 6

Adalimumab

  • 160 mg

  • Then 80 mg

  • Then 40 mg q2 weeks

Alternative

  • Vedolizumab

  • Ustekinumab

Perianal Crohn's

Metronidazole

  • 500 mg PO TID

PLUS

Ciprofloxacin

  • 500 mg PO BID

(Bridge until biologic optimization)

VTE Prophylaxis (ALL ADMITTED IBD)

Enoxaparin

  • 40 mg SQ daily

IBD = ~3× increased VTE risk

Nutrition

Iron Deficiency

IV Iron

  • Ferric carboxymaltose 500–1000 mg IV

Terminal Ileal Crohn's

Vitamin B12

  • 1000 mcg IM monthly

Dietitian Consult

  • Weight loss

  • Malnutrition

  • Poor PO intake

Hold Medications

Hold

  • NSAIDs

  • Loperamide

  • Opioids if possible

Avoid

  • Starting steroids before C. diff testing

Consults

Gastroenterology (All Moderate-Severe Flares)

General Surgery

Severe UC

  • Consult on admission

Crohn's

  • Abscess

  • Fistula

  • Obstruction

  • Perforation

Colorectal Surgery

  • Toxic megacolon

  • Colectomy consideration

Infectious Disease

  • CMV

  • Refractory infection

Nutrition

PT/OT

  • Deconditioning

Nursing Orders

Monitoring

  • Strict I&O

  • Stool count

  • Daily weights

  • Vital signs q4 hr

Diet

  • Low-residue diet

  • NPO if toxic megacolon

Notify Physician Immediately

  • Increasing abdominal distension

  • Fever

  • Bloody diarrhea worsening

  • Peritoneal signs

  • Tachycardia