What is the initial management for a patient presenting with right lower quadrant (RLQ) abdominal pain?

Initial Management of Right Lower Quadrant Abdominal Pain

Order contrast-enhanced CT of the abdomen and pelvis with IV contrast as the primary diagnostic imaging study for any patient presenting with right lower quadrant pain. 1, 2

Immediate Clinical Assessment

Obtain focused history targeting these specific high-yield elements:

• Last bowel movement and passage of flatus – absence suggests bowel obstruction 1, 2
• Prior abdominal surgery – 85% sensitivity and 78% specificity for adhesive small bowel obstruction 1, 2
• Rectal bleeding or unexplained weight loss – suggests colorectal malignancy (60% of large bowel obstructions) 1, 2
• Chronic constipation history – suggests volvulus or diverticular disease 1
• Cardiovascular comorbidities – raises concern for mesenteric ischemia 2

Physical examination should document:

• Fever and localized peritoneal signs – present in appendicitis but often blunted in elderly patients 1, 2
• Rebound tenderness – significantly more common in appendicitis versus other causes 3

Laboratory Testing

Order complete blood count and C-reactive protein:

• Elevated WBC and neutrophil percentage – significantly associated with appendicitis (p < 0.001) 3
• Elevated CRP – significantly associated with appendicitis (p < 0.001) 3
• Normal labs do NOT exclude serious pathology – elderly patients frequently have blunted inflammatory responses despite perforation or serious infection 2

Imaging Strategy

CT abdomen/pelvis with IV contrast is the single most appropriate initial imaging modality with the following performance characteristics:

• 95% sensitivity and 94% specificity for appendicitis 2
• 94.3% concordance with final clinical diagnosis for alternative pathologies 2
• Identifies bowel obstruction, diverticulitis, malignancy, and vascular emergencies in one study 2

Oral contrast may be added for better bowel visualization but is not mandatory 2. Do not delay imaging for oral contrast administration. 1

Alternative imaging considerations:

• Ultrasound – reserve for pregnant patients or when radiation exposure is a primary concern 1
• MRI – approaching CT in accuracy but less widely available; use when CT is contraindicated 1

Differential Diagnosis Priority List

While awaiting imaging, consider these diagnoses in order of frequency and surgical urgency:

1. Appendicitis – most common surgical cause of RLQ pain, but presents atypically in elderly with higher perforation rates 1, 2
2. Right-sided colonic diverticulitis – increasingly common with age, precisely mimics appendicitis 2
3. Bowel obstruction – particularly adhesive small bowel obstruction if prior surgery 1, 2
4. Colorectal malignancy – accounts for 60% of large bowel obstructions in elderly 1, 2
5. Mesenteric ischemia – critical diagnosis in elderly with cardiovascular disease 2
6. Gynecologic pathology – ovarian cyst, pelvic inflammatory disease 2, 4
7. Urinary tract pathology – ureteral stone, pyelonephritis 1, 4

Immediate Management While Awaiting Imaging

Initiate these interventions simultaneously with imaging workup:

• NPO status 2
• IV fluid resuscitation 2
• Nasogastric decompression if bowel obstruction suspected 2
• Broad-spectrum antibiotics if peritoneal signs present 2
• Surgical consultation – do not delay for elderly patients or those with peritoneal signs 2

Critical Pitfalls to Avoid

Atypical presentations are the norm in elderly patients – they frequently lack classic symptoms, have blunted inflammatory responses, and present later in disease course with higher complication rates 2. Do not be falsely reassured by:

• Normal vital signs in elderly patients 2
• Absence of fever 2
• Normal white blood cell count 2
• Mild or vague symptoms 2

Never rely on clinical scoring systems alone – the Alvarado score demonstrates mixed results and does not improve diagnostic accuracy sufficiently to replace imaging 1. Clinical determination without imaging has an unacceptably high negative appendectomy rate of up to 25% 1.

Do not delay imaging for "active observation" in patients with concerning features – increased imaging utilization decreases negative appendectomy rates without increasing perforation rates from diagnostic delays 1.