What is the initial physical assessment for a patient presenting with lower left quadrant (LLQ) abdominal pain?

Physical Assessment for Left Lower Quadrant Abdominal Pain

Begin with a focused physical examination assessing for peritoneal signs, localization of maximal tenderness, and fever, as clinical diagnosis alone is unreliable with misdiagnosis rates of 34-68%. 1

Critical Physical Examination Components

Primary Assessment Points

• Assess for peritoneal signs including diffuse abdominal tenderness, guarding, rebound tenderness, or absent bowel sounds, which indicate possible perforation requiring emergent surgery 1
• Palpate for localized left lower quadrant tenderness as the classic triad of LLQ pain, fever, and leukocytosis is present in only 25% of diverticulitis cases 1
• Evaluate vital signs for fever, tachycardia, tachypnea, or signs of shock, which suggest complicated disease or sepsis 1

Red Flag Physical Findings Requiring Emergency Evaluation

• Signs of peritonitis (diffuse tenderness, guarding, rebound) indicate perforation with potential fecal contamination and septic shock 1
• Abdominal distension with inability to pass gas or stool is present in 90% of large bowel obstructions and 65% of cases respectively, suggesting complete obstruction 1
• Toxic appearance characterized by fever, rapid breathing, rapid heartbeat, confusion, or septic shock requires immediate intervention 1
• Severe abdominal tenderness with guarding combined with vomiting or bloody stools mandates emergency department evaluation 1

Initial Laboratory Assessment

Essential Laboratory Tests

• Complete blood count with differential as elevated WBC suggests infectious or inflammatory process 2
• C-reactive protein as CRP >50 mg/L significantly increases likelihood of inflammatory pathology; when combined with LLQ tenderness and absence of vomiting, diagnostic accuracy reaches 97% (though this triad occurs in only 24% of patients) 1
• Lipase to assess for pancreatitis 2
• Urinalysis to evaluate for renal pathology including pyelonephritis or nephrolithiasis 2
• Pregnancy testing for women of reproductive age before ordering CT imaging 1

Common Pitfalls to Avoid

• Do not rely on clinical assessment alone as the classic triad of LLQ pain, fever, and leukocytosis is present in only 25% of diverticulitis cases, and clinical diagnosis has 34-68% misdiagnosis rates 1
• Consider atypical presentations including right-sided appendicitis with long appendix projecting into LLQ, or left-sided appendicitis with situs inversus totalis 3
• Recognize that absence of fever does not exclude serious pathology as many patients with complicated diverticulitis present without the complete classic triad 1
• Perform adequate serial examinations in patients with uncertain clinical features, as local peritonitis can develop during observation 3

Imaging Decision Algorithm

Standard Approach

• CT abdomen and pelvis with IV contrast is the preferred imaging modality for most patients with LLQ pain, with 98% diagnostic accuracy 1
• CT with IV contrast provides superior detection of complications (abscess, perforation, fistula), identifies alternative diagnoses, and reduces hospital admissions by >50% 1

Special Population Considerations

• Premenopausal women with suspected gynecologic pathology should receive pelvic/transvaginal ultrasound as initial imaging 4, 1
• Pregnant patients require ultrasonography or MRI to avoid radiation exposure 1
• Young patients where radiation is a concern may benefit from ultrasound initially 2

When to Modify Imaging Strategy

• CT without IV contrast is acceptable when IV contrast is contraindicated, though less accurate for detecting abscesses (rated 6/9 vs 8/9 for contrast-enhanced) 1
• Plain radiography is not useful as initial testing due to limited sensitivity and missing most acute pathology 4, 2