What is the appropriate assessment and management plan for an otherwise healthy adult with isolated right lower‑quadrant abdominal pain, no other findings, whose relative had gastrointestinal symptoms, and who refuses to go to the emergency department?

Management Plan for Adult with Isolated RLQ Pain Refusing Emergency Department Evaluation

This patient requires same-day outpatient imaging with CT abdomen/pelvis with IV contrast, followed by mandatory 24-hour clinical reassessment, because clinical examination alone misses appendicitis in 34-68% of cases and the absence of fever or leukocytosis does not exclude early appendicitis. 1

Immediate Assessment & Risk Stratification

Critical Clinical Features to Document

• Assess for peritoneal signs – Specifically evaluate for rebound tenderness, guarding, or rigidity at McBurney's point, as these findings dramatically increase appendicitis probability despite normal vital signs 1
• Pain characteristics – Document whether pain is constant versus intermittent, whether it migrated from periumbilical region to RLQ (classic appendicitis pattern), and severity on 0-10 scale 1
• Associated symptoms – Explicitly ask about anorexia (key feature), nausea, vomiting, and ability to tolerate oral intake 1
• Fever measurement – Note that fever is absent in approximately 50% of appendicitis cases, so its absence does not reduce risk 1, 2

Essential Laboratory Testing

• Complete blood count – Normal WBC occurs commonly in early appendicitis and does not exclude the diagnosis 1, 2
• C-reactive protein – Similarly, normal CRP does not rule out appendicitis, particularly in early presentations 2
• Urinalysis – Obtain to evaluate for UTI/nephrolithiasis, but recognize that sterile pyuria can result from adjacent appendiceal inflammation 1
• Pregnancy test (β-hCG) – Mandatory in all reproductive-age women before any imaging to exclude ectopic pregnancy 3, 1

Diagnostic Imaging Strategy

Primary Recommendation: CT Abdomen/Pelvis with IV Contrast

Order CT abdomen/pelvis with IV contrast (no oral contrast needed) as the definitive diagnostic test because:

• Sensitivity 85.7-100% and specificity 94.8-100% for appendicitis detection 1, 4
• Identifies alternative diagnoses in 23-45% of cases presenting with RLQ pain, fundamentally changing management 1, 4
• Detects gynecologic pathology in 21.6% and GI conditions in 46% of alternative diagnoses 1
• IV contrast alone (without oral) provides rapid acquisition without compromising diagnostic accuracy 1

Critical Pitfall to Avoid

• Do not discharge based solely on normal labs and absence of fever – This approach risks missing early appendicitis, as 15.6% of confirmed appendicitis cases present with isolated RLQ tenderness and completely normal inflammatory markers 2
• Do not rely on clinical examination alone – Negative appendectomy rates reach 25% when imaging is omitted, versus 1.7-7.7% with preoperative CT 1

Management Algorithm Based on Imaging Results

If CT Confirms Appendicitis

• Immediate surgical consultation for appendectomy 1
• Initiate antimicrobial therapy while awaiting surgery 1
• If perforated with abscess – Consider percutaneous drainage followed by interval appendectomy 1

If CT Shows Alternative Diagnosis

• Gynecologic pathology (ovarian torsion, ruptured cyst, PID) – Gynecology consultation 1
• Right-sided diverticulitis – Medical management with antibiotics and bowel rest 1
• Nephrolithiasis – Urology referral and pain management 1
• Inflammatory bowel disease – Gastroenterology referral 3

If CT is Negative or Equivocal

• Mandatory 24-hour follow-up with repeat clinical examination to assess for evolving peritoneal signs 1
• Serial abdominal exams every 6-12 hours if symptoms persist during observation 1
• Repeat CBC to monitor for developing leukocytosis 1
• Proceed to repeat imaging if symptoms worsen or new peritoneal signs develop 1

Safety-Netting Instructions (Critical for Outpatient Management)

Return Precautions – Instruct Patient to Seek Immediate Emergency Care If:

• Development of fever (temperature >38°C/100.4°F) 1
• Worsening or intensifying abdominal pain 1
• New onset of vomiting or inability to tolerate oral intake 1
• Development of rebound tenderness, guarding, or abdominal rigidity 1
• Syncope, dizziness, or signs of hemodynamic instability 3

Supportive Care While Awaiting Imaging

• Maintain hydration with clear liquids 1
• Mild analgesics only – Avoid opioids which can mask evolving symptoms 1
• Nothing by mouth if surgical intervention becomes likely 1

Rationale for This Approach

Why Imaging Cannot Be Deferred

• Clinical scoring systems (Alvarado, PAS) have not improved diagnostic accuracy sufficiently to rely on examination alone 5
• Family history of GI symptoms raises concern for infectious gastroenteritis but does not exclude appendicitis, which can present with similar prodrome 1
• 15.6% of pathologically confirmed appendicitis cases present with isolated RLQ pain and completely normal inflammatory markers 2
• Ultrasonography complemented by CT when equivocal achieved 96.1% correlation with final pathology in patients with isolated RLQ tenderness 2

Why 24-Hour Follow-Up is Non-Negotiable

• Measurable false-negative rates exist even in low-risk presentations 1
• Appendicitis evolves over hours – Early presentations may lack classic findings that develop later 1
• Delayed diagnosis increases perforation risk with associated higher morbidity 1

Special Considerations

If Patient is Female of Reproductive Age

• Consider transvaginal ultrasound before or in addition to CT to evaluate for gynecologic causes (ovarian torsion, ectopic pregnancy, hemorrhagic cyst) 1
• Staged ultrasound-then-CT approach achieves 99% sensitivity and 91% specificity while minimizing radiation 1

Documentation Requirements

• Document detailed informed refusal if patient declines recommended imaging or ED evaluation 1
• Explicitly document return precautions provided and patient's understanding 1
• Arrange definitive follow-up appointment within 24 hours with clear plan for escalation 1