What is the workup for a patient presenting with left lower abdominal pain, nausea, and vomiting for 2 days?

Workup for Left Lower Abdominal Pain with Nausea and Vomiting

The initial workup for a patient with left lower abdominal pain, nausea, and vomiting for two days should include a focused history, physical examination, laboratory tests, and appropriate imaging, with CT abdomen and pelvis with IV contrast being the most valuable diagnostic tool.

Initial Assessment

History - Focus on:

• Pain characteristics:
  • Location (confined to LLQ or radiating)
  • Onset and progression
  • Quality (cramping, sharp, colicky)
  • Severity
  • Exacerbating/relieving factors
• Nausea and vomiting:
  • Frequency and content of emesis
  • Relationship to meals
  • Response to any home remedies
• Associated symptoms:
  • Changes in bowel habits (diarrhea, constipation)
  • Fever or chills
  • Urinary symptoms
  • Gynecological symptoms in women

Physical Examination:

• Vital signs (tachycardia may indicate significant volume depletion or inflammation) 1
• Abdominal examination:
  • Tenderness (location, guarding, rebound)
  • Distension
  • Bowel sounds
  • Masses or organomegaly
• Pelvic/rectal examination to assess for masses or tenderness

Laboratory Tests

• Complete blood count (evaluate for leukocytosis suggesting inflammation/infection)
• Comprehensive metabolic panel (assess electrolyte imbalances, renal and liver function)
• Urinalysis (rule out urinary tract infection or nephrolithiasis)
• Pregnancy test for women of childbearing age
• Serum lactate (if concerned for mesenteric ischemia) 1
• C-reactive protein and procalcitonin (markers of inflammation/infection) 1

Imaging Studies

First-line:

• CT abdomen and pelvis with IV contrast
  • Most valuable for evaluating left lower quadrant pain
  • Can identify diverticulitis, bowel obstruction, inflammatory bowel disease, mesenteric ischemia, and other pathologies 1
  • High sensitivity and specificity (95-100%) for detecting vascular abnormalities 1

Alternative/Additional Imaging:

• Abdominal X-ray
  • Limited utility but may show obstruction, perforation, or ileus
  • Should not delay more definitive imaging if clinical suspicion is high 1
• Ultrasound
  • Useful for female patients to evaluate gynecological causes
  • Can assess for gallbladder disease if pain radiates to upper quadrants
  • Limited by bowel gas and obesity 1

Differential Diagnosis to Consider

Common causes of left lower abdominal pain with nausea/vomiting:

1. Diverticulitis
2. Bowel obstruction (partial or complete)
3. Inflammatory bowel disease
4. Mesenteric ischemia (especially in elderly patients) 1
5. Gastroenteritis
6. Urolithiasis
7. Gynecological causes in women (ovarian torsion, PID)
8. Hernia (including rare types like sciatic hernia) 2

Management Approach

1. Fluid resuscitation for dehydration from vomiting

2. Antiemetic therapy:

   • Ondansetron 4-8mg IV/PO (first-line due to favorable side effect profile) 3, 4
   • Prochlorperazine 5-10mg IV (monitor for akathisia) 4
   • Promethazine 12.5-25mg IV/IM (when sedation is desirable) 4

3. Pain management:

   • NSAIDs (ketorolac 15-30mg IV) as first-line analgesic 1
   • Opioids only if severe pain unresponsive to NSAIDs

4. Definitive management based on diagnosis from workup

Important Considerations

• Tachycardia is a critical warning sign that may indicate serious pathology requiring urgent intervention 1
• Elderly patients may present with atypical or subtle symptoms despite serious underlying pathology
• Consider surgical consultation early if peritoneal signs, obstruction, or ischemia are suspected
• For patients with recurrent episodes, consider chronic causes like cyclic vomiting syndrome 1, 5

Pitfalls to Avoid

• Delaying imaging in patients with concerning symptoms
• Attributing symptoms to gastroenteritis without adequate workup
• Missing gynecological emergencies in female patients
• Overlooking mesenteric ischemia in elderly patients with risk factors
• Failing to reassess patients who don't improve with initial management

Remember that left lower quadrant pain with nausea and vomiting can represent serious pathology requiring prompt diagnosis and management to prevent complications and reduce morbidity and mortality.