What is the appropriate management for a patient with right lower abdominal pain and bloating, suspected of having appendicitis or other conditions such as inflammatory bowel disease?

Management of Right Lower Abdominal Pain and Bloating

Obtain CT abdomen and pelvis with IV contrast as the definitive diagnostic test, which achieves 95% sensitivity and 94% specificity for appendicitis while simultaneously identifying alternative diagnoses in 23-45% of cases presenting with right lower quadrant pain. 1, 2

Immediate Diagnostic Workup

Essential Pre-Imaging Steps

• Pregnancy test is mandatory in women of reproductive age before any imaging to exclude ectopic pregnancy 2
• Complete blood count to assess for leukocytosis (present in appendicitis but normal WBC reduces probability when combined with benign presentation) 3
• Urinalysis to exclude urinary tract infection or nephrolithiasis 2

Imaging Protocol

• CT abdomen/pelvis with IV contrast without enteral contrast is the gold standard, providing 90-100% sensitivity and 94.8-100% specificity for appendicitis while avoiding delays from oral contrast administration 1, 3
• CT identifies critical alternative diagnoses including right colonic diverticulitis (8%), ureteral stones, intestinal obstruction (3%), gynecologic pathology (21.6%), and other gastrointestinal conditions (46%) 3
• Ultrasound may be considered first-line in children to avoid radiation, followed by CT if nondiagnosive (staged approach achieves 99% sensitivity and 91% specificity) 3

Management Algorithm Based on CT Results

If CT Confirms Appendicitis (Appendix >8.2mm)

• Immediate surgical consultation for appendectomy regardless of clinical improvement, as probability of true appendicitis exceeds 90% 3
• Initiate IV antibiotics at time of diagnosis 2
• Admit patient for surgical management 4

If CT Shows Alternative Diagnosis

• Right colonic diverticulitis or inflammatory bowel disease: May manage outpatient with antibiotics if mild, or admit if severe 4
• Gynecologic pathology (ovarian torsion, ruptured cyst, tubo-ovarian abscess): Emergency gynecologic surgery for torsion; conservative management or gynecology consultation for ruptured cyst; IV antibiotics ± drainage for abscess 2
• Constipation/stool burden: Initiate bowel regimen with stool softeners and osmotic laxatives, provide symptomatic pain relief, reassess in 24-48 hours 5

If CT is Negative

• Conservative management is appropriate as only 14% require hospitalization and 4% need surgical intervention when CT shows no acute diagnosis 5
• Initiate bowel regimen for symptomatic relief 5
• Mandatory 24-hour follow-up to ensure symptom improvement and exclude evolving pathology 5, 3
• Provide strict return precautions: fever, persistent vomiting, worsening pain, peritoneal signs, or inability to tolerate oral intake 5, 3

Critical Clinical Pitfalls to Avoid

Do Not Rely on Absence of Fever

• Fever is absent in approximately 50% of appendicitis cases, making it an unreliable exclusion criterion 3
• Clinical determination alone has unacceptably high negative appendectomy rates of 25% without imaging 1, 3

Do Not Discharge Without Clear Safety Net

• Avoid unnecessary repeat imaging if symptoms are stable or improving, as this increases radiation without changing management 5
• Do not dismiss persistent pain that fails to improve with conservative management—consider alternative diagnoses and clinical reassessment 5
• Reimage only if clinical deterioration occurs or new concerning features develop 5

Do Not Delay Imaging in Evolving Presentations

• NSAIDs can mask evolving symptoms and delay diagnosis 3
• Serial abdominal examinations every 6-12 hours are essential during observation periods to assess for progression of peritoneal signs 3
• If symptoms persist or worsen during observation, proceed immediately to CT imaging 3

Special Considerations

Low-Risk Presentations

• Patients with low clinical suspicion (no fever, normal WBC, benign exam) can be discharged with mandatory 24-hour follow-up rather than admission 3
• Clinical scoring systems should guide imaging decisions, not reflexive CT ordering in all cases 3
• Watch for development of peritoneal signs (guarding, rigidity, rebound) which warrant immediate reconsideration and imaging 3

Borderline CT Findings

• Appendix 7-8mm without clear periappendiceal infiltration: Hospital observation for 24 hours with serial abdominal exams 3
• Appendix >8.2mm with periappendiceal infiltration: Immediate surgical consultation regardless of clinical status 3