What is the appropriate management for an elderly male patient with acute left lower abdominal pain, without nausea, vomiting, fever, or changes in bowel movements?

Management of Elderly Male with Left Lower Abdominal Pain

This elderly male patient requires CT scan with IV contrast to confirm or exclude acute left colonic diverticulitis, as clinical presentation alone is insufficient for diagnosis in this age group, and elderly patients frequently present without typical symptoms like fever. 1

Why Clinical Assessment Alone is Inadequate

The absence of fever, nausea, vomiting, and presence of normal bowel movements does not exclude serious pathology in elderly patients. 1

• Only 50% of patients older than 65 years with acute left colonic diverticulitis have pain in the lower quadrants, only 17% have fever, and 43% do not have leukocytosis. 1
• Clinical diagnosis of acute left colonic diverticulitis has a sensitivity of only 0.68 in the general population, and is even less reliable in elderly patients. 1
• Do not rely on the absence of fever or normal inflammatory markers to rule out complicated disease - nearly 5% of patients with severe diverticulitis present without fever or leukocytosis. 1

Immediate Diagnostic Approach

Obtain CT scan with IV contrast immediately to confirm the diagnosis and distinguish complicated from uncomplicated diverticulitis. 1

• CT has 98-99% sensitivity and 99-100% specificity for diagnosing diverticulitis and identifying complications. 2
• The scan should specifically evaluate for extraluminal air, abscess formation, free fluid, and bowel wall thickening with pericolonic fat stranding. 2
• If CT with IV contrast is contraindicated (severe renal disease or contrast allergy), use ultrasound, MRI, or CT without contrast as alternatives. 1

Laboratory Testing

While awaiting imaging, obtain:

• Complete blood count with differential 2
• C-reactive protein (CRP) - though a low CRP does not exclude complicated diverticulitis, as 39% of patients with complicated episodes have CRP below 175 mg/L. 1, 2
• Lactate level if any concern for sepsis 2

Critical pitfall: Do not use normal inflammatory markers to exclude diverticulitis or delay imaging. 1, 2

Management Based on CT Findings

If Uncomplicated Diverticulitis (WSES Stage 0)

• Antibiotics can be avoided in immunocompetent elderly patients without sepsis-related organ failures. 1
• Outpatient management may be appropriate if patient is stable and has reliable follow-up. 1

If Localized Complicated Diverticulitis with Pericolic Air/Fluid (WSES Stage 1a)

• Administer antibiotic therapy - this is recommended for elderly patients with these findings. 1
• Broad-spectrum coverage for gram-negative and anaerobic organisms. 1

If Abscess Present

• Abscess <4 cm: IV antibiotics alone for 7 days. 1, 2
• Abscess ≥4 cm: IV antibiotics PLUS percutaneous CT-guided drainage. 1, 2

If Free Air or Peritonitis

• Immediate surgical consultation - non-operative management is not recommended. 1, 2

Disposition and Follow-up

• Admit elderly patients with any complicated findings, given the significantly higher mortality risk (9.7% in patients 65-79 years, 17.8% in patients above 80 years). 2
• If imaging is normal and alternative diagnosis is not identified, consider other causes of left lower abdominal pain including colonic malignancy, ischemic colitis, or urologic pathology. 3, 4
• Plan early colonoscopy after resolution of acute episode to exclude malignancy or other colonic pathology. 1

Key Clinical Pitfalls to Avoid

• Do not assume benign disease based on lack of fever or normal vital signs - elderly patients present atypically. 1, 2
• Do not delay imaging based on normal laboratory values - misdiagnosis rates are 34-68% without imaging. 2
• Do not discharge without imaging - the differential diagnosis in elderly patients with left lower abdominal pain includes life-threatening conditions requiring urgent intervention. 4, 5