What is the best course of action for a 64-year-old male with a history of Ulcerative Colitis (UC) and Crohn's disease, presenting with right lower quadrant (RLQ) and right flank pain for 4 days, who has been taking ibuprofen (Advil) and Excedrin (acetaminophen, aspirin, and caffeine) daily for 2 years, with lab results showing impaired renal function (elevated creatinine) and anemia (low hemoglobin and hematocrit)?

Management of RLQ and Right Flank Pain in IBD Patient with Chronic NSAID Use and Renal Impairment

This patient requires immediate discontinuation of ibuprofen and Excedrin, urgent cross-sectional imaging (CT with IV contrast) to evaluate for IBD complications, and comprehensive laboratory workup to assess disease activity and exclude infection. 1, 2, 3

Immediate Actions

Stop Nephrotoxic and IBD-Exacerbating Medications

• Discontinue ibuprofen immediately as it causes renal impairment (elevated creatinine 1.31), can precipitate acute renal failure with chronic use, and is associated with IBD flare activation when used ≥5 times/month 3, 4, 5
• Stop Excedrin (contains aspirin) as NSAIDs have been implicated in IBD flare and should be avoided; paracetamol/acetaminophen alone is the preferred first-line analgesic for IBD patients 1
• The patient's microcytic anemia (MCV 82, MCH 24.8, MCHC 30.3) with low hemoglobin (11.8) suggests chronic GI blood loss, a known complication of chronic NSAID use in addition to IBD-related bleeding 3

Urgent Diagnostic Workup

• Obtain CT abdomen/pelvis with IV contrast immediately to evaluate for IBD complications including abscess, fistula, stricture, or perforation given 4-day history of localized pain in a patient with both UC and Crohn's disease 1, 2
• The combination of RLQ and right flank pain raises concern for ileal/ileocecal Crohn's involvement with potential complications such as abscess (which can present with flank pain) or renal calculi (extra-intestinal manifestation) 1

Comprehensive Laboratory Assessment

• Complete the following labs urgently: full blood count with differential (already done), comprehensive metabolic panel (already done), C-reactive protein, erythrocyte sedimentation rate, serum albumin, fecal calprotectin if available 1, 6
• Rule out infectious causes: blood cultures, stool cultures, and Clostridium difficile toxin test are mandatory before escalating immunosuppression 1, 6
• The elevated urine specific gravity (>1.030) suggests dehydration, which combined with chronic NSAID use increases acute renal failure risk 3, 4

Assessment of Disease Activity vs. Complications

Distinguish IBD Flare from Mechanical Complications

• RLQ pain in Crohn's disease may indicate active inflammation, stricturing disease with obstruction, abscess formation, or fistulizing disease 1
• Right flank pain suggests possible renal calculi (extra-intestinal manifestation occurring in up to 46% of IBD patients), abscess extending to retroperitoneum, or NSAID-induced renal tubular acidosis 1, 7
• The 4-day duration without systemic signs of sepsis (WBC 7.3 is normal) makes free perforation less likely, but localized perforation with contained abscess remains possible 1, 2

Evaluate for NSAID-Related Complications

• Chronic ibuprofen use for 2 years significantly increases risk of renal impairment, with the patient showing elevated creatinine (1.31) and concentrated urine 3, 4, 8
• NSAID-induced renal tubular acidosis can present with non-specific symptoms and electrolyte abnormalities; check serum bicarbonate, chloride, and urinary pH 7
• The microcytic anemia pattern suggests chronic GI blood loss from NSAID-induced ulceration superimposed on IBD, requiring evaluation for occult bleeding 3

Initial Management Algorithm

Resuscitation and Supportive Care

• Initiate IV fluid resuscitation to correct dehydration (evidenced by high urine specific gravity) and support renal function 2, 6
• Administer low-molecular-weight heparin for VTE prophylaxis given IBD and potential immobility 2, 6
• Correct electrolyte abnormalities and consider transfusion if hemoglobin drops further or patient is symptomatic 2, 6

Empiric Antibiotic Therapy (If Infection/Abscess Suspected)

• If imaging reveals abscess or clinical suspicion is high, initiate broad-spectrum antibiotics covering Gram-negative aerobic bacteria, Gram-positive streptococci, and obligate anaerobes according to local resistance patterns 1, 9, 6
• Small abscesses (<3 cm) can be treated with antibiotics alone, though recurrence rate is high (37-50%); larger abscesses require percutaneous drainage 9

Medical Management of IBD Flare (If No Abscess)

• If hemodynamically stable without evidence of abscess/perforation, consider IV corticosteroids (not oral given potential malabsorption with active disease) for acute severe colitis or Crohn's flare 1, 2, 6
• Assess response to corticosteroids by day 3; if no improvement, escalate to advanced therapy (biologics or small molecules) 1, 6
• Continue or optimize maintenance 5-ASA therapy for ulcerative colitis component 1

Critical Pitfalls to Avoid

Do Not Delay Imaging for Empiric PPI Therapy

• Pantoprazole or other PPIs should NOT be used as empiric therapy for undifferentiated acute abdomen; this patient needs surgical evaluation and imaging, not acid suppression 2
• The priority is establishing diagnosis through imaging and determining if surgical intervention is needed 2

Recognize High-Risk Medication Combinations

• Avoid combining corticosteroids with biologics while active infection/abscess is present, as this combination significantly increases risk of intra-abdominal sepsis and mortality 9, 6
• If abscess is identified, complete antibiotic course and achieve clinical/radiologic resolution before initiating or continuing biologic therapy 9

Monitor for Surgical Indications

• Surgical consultation is mandatory if: free perforation with peritonitis, hemodynamic instability, clinical deterioration despite medical therapy, or large abscess not amenable to percutaneous drainage 1, 2
• For stricturing disease causing obstruction not responsive to medical therapy and not amenable to endoscopic dilation, surgery is indicated 1

Renal Protection Strategy

Optimize Renal Function

• Discontinue all nephrotoxic agents (ibuprofen, aspirin in Excedrin) immediately 3, 4
• Ensure adequate hydration and avoid contrast if eGFR <30 mL/min (calculate based on creatinine 1.31) 1
• Monitor creatinine, electrolytes, and urinalysis closely; NSAID-induced renal impairment is usually reversible but may require months and occasionally dialysis 4, 7

Alternative Analgesia

• Use acetaminophen (paracetamol) as first-line analgesic for IBD patients, as it lacks peripheral prostaglandin inhibition and has minimal renal effects when used appropriately 1, 8
• Avoid opioids due to risk of narcotic bowel syndrome, gut dysmotility, dependence, and increased infection/mortality risk in IBD 1
• Consider tricyclic antidepressants as adjuvant analgesics for chronic pain management 1

Follow-Up and Monitoring

Short-Term (48-72 Hours)

• Reassess clinical status, inflammatory markers (CRP), and renal function daily 1, 6
• If no improvement with initial therapy, re-evaluate for missed complications or alternative diagnoses 6
• Ensure infectious workup results are reviewed and antibiotic therapy adjusted accordingly 1, 6

Long-Term Management

• Once acute episode resolves, optimize IBD maintenance therapy to prevent future flares and reduce need for analgesics 1
• Monitor hemoglobin/hematocrit periodically given chronic anemia and history of NSAID use 3
• Educate patient about avoiding NSAIDs and recognizing early signs of IBD flare to prevent similar presentations 1, 5