What is the appropriate treatment for a patient with abdominal pain, diarrhea, leukocytosis, and neutrophilia?

Management of Abdominal Pain with Diarrhea and Leukocytosis

This patient requires immediate broad-spectrum antibiotic therapy with an anti-pseudomonal beta-lactam (piperacillin-tazobactam) or carbapenem, along with urgent CT imaging to rule out life-threatening complications, while simultaneously testing for Clostridium difficile infection. 1

Immediate Diagnostic Priorities

The combination of abdominal pain, diarrhea, and leukocytosis (WBC 13.1 with neutrophilia 10.1) demands urgent evaluation for infectious and inflammatory causes that carry significant mortality risk if missed:

Critical Laboratory Testing

• Obtain C-reactive protein (CRP) and procalcitonin immediately - these markers have superior diagnostic accuracy compared to WBC count alone for identifying serious infectious complications 2
• Test stool for C. difficile toxin using a two-step approach (enzyme immunoassay for glutamate dehydrogenase plus toxin detection or nucleic acid amplification test) 1
• Draw at least two sets of blood cultures if fever is present, as leukocytosis suggests possible bacteremia 1
• Serum electrolytes, creatinine, and lactate to assess for dehydration and bowel ischemia 1, 2

Imaging Requirements

CT abdomen/pelvis with IV contrast is mandatory - do not rely on ultrasound or plain films alone in this setting 1. The CT must specifically evaluate for:

• Bowel wall thickening >5mm (>10mm carries 60% mortality risk in certain populations) 1
• Free air suggesting perforation 2
• Fluid collections or abscesses 2
• Signs of bowel ischemia or obstruction 1

Empiric Antibiotic Therapy

Start broad-spectrum antibiotics immediately while awaiting diagnostic results - do not delay for test results if the patient appears ill 1:

• First-line: Piperacillin-tazobactam OR a carbapenem (imipenem, meropenem, or doripenem) with anti-pseudomonal activity 1
• Add empiric C. difficile coverage (oral vancomycin 125mg four times daily OR metronidazole 500mg three times daily) if recent antibiotic exposure, healthcare contact, or high clinical suspicion 1
• Continue antibiotics until clinical improvement and resolution of leukocytosis 1

The rationale: leukocytosis with neutrophilia in the setting of abdominal pain and diarrhea suggests bacterial infection or inflammatory enterocolitis, both requiring immediate antimicrobial coverage 1.

Risk Stratification for Surgical Consultation

Obtain early surgical consultation - mortality increases dramatically if surgical disease is missed in this population 1. Immediate surgical exploration is required if any of the following develop:

• Signs of perforation or peritonitis (though these may be subtle) 1, 2
• Bowel ischemia on imaging 1
• Clinical deterioration despite 24-48 hours of appropriate medical therapy 1, 2
• Toxic megacolon 1
• Hemodynamic instability (hypotension, tachycardia, decreased urine output) 2

Supportive Management

• Bowel rest with IV hydration - NPO status until clinical improvement 1
• Serial abdominal examinations every 4-6 hours to detect clinical deterioration 2
• Correct electrolyte abnormalities aggressively 1
• Hold antimotility agents (loperamide, opiates) until infectious causes excluded 1

Differential Diagnosis Considerations

The clinical presentation warrants consideration of several specific entities:

Clostridium difficile Infection

Most likely if recent antibiotic exposure (within 90 days), healthcare contact, or persistent symptoms 1. Leukocytosis is a hallmark finding 3, 4. Treatment should not await confirmatory testing if suspicion is high 1.

Neutropenic Enterocolitis (if applicable)

If this patient has recent chemotherapy or immunosuppression, neutropenic enterocolitis becomes the primary concern despite the elevated WBC (which may represent relative leukocytosis in recovery phase) 1. This carries 29.5% mortality if imaging shows bowel wall thickening 1.

Bacterial Gastroenteritis

Consider testing for Salmonella, Shigella, Campylobacter, and Shiga toxin-producing E. coli if community-acquired diarrhea, though empiric antibiotics should not await results 1.

Common Pitfalls to Avoid

• Do not assume normal vital signs exclude serious pathology - fever and peritoneal signs may be absent or subtle, especially in immunocompromised patients 1
• Do not rely on stool cultures alone - diagnostic yield is <5% in many settings; C. difficile testing is more critical 1
• Do not delay CT imaging - ultrasound and plain films have insufficient sensitivity for life-threatening complications 1
• Do not withhold antibiotics pending culture results if the patient appears systemically ill 1

Follow-up and Reassessment

If no improvement within 48 hours of appropriate therapy:

• Repeat imaging to evaluate for complications 1, 2
• Broaden antimicrobial coverage if not already done 1
• Consider non-infectious etiologies (inflammatory bowel disease, ischemic colitis) 1
• Escalate to surgical intervention if indicated 1