What is the appropriate diagnosis and treatment for a patient in their early 60s with right lower quadrant pain?

Right Lower Quadrant Pain in Early 60s Patient

CT abdomen and pelvis with IV contrast is the imaging modality of choice for evaluating right lower quadrant pain in this age group, as it provides the highest diagnostic accuracy for the most likely and serious etiologies including appendicitis, diverticulitis, bowel obstruction, and malignancy. 1

Initial Clinical Assessment

The differential diagnosis in a patient in their early 60s with right lower quadrant (RLQ) pain is broad and includes:

• Appendicitis - remains possible at any age, though less common than in younger patients 1, 2
• Bowel obstruction - particularly adhesive small bowel obstruction if prior abdominal surgery history (85% sensitivity, 78% specificity for predicting adhesive obstruction) 1
• Colorectal malignancy - accounts for approximately 60% of large bowel obstructions in adults 1
• Diverticulitis - though more commonly left-sided, right-sided diverticulitis occurs 1
• Inflammatory bowel disease, hernias, or other pathology 1

Key historical elements to elicit include:

• Prior abdominal surgeries - strongly suggests adhesive obstruction 1
• Last bowel movement and passage of flatus - obstruction indicators 1
• Unexplained weight loss or rectal bleeding - suggests malignancy 1
• Fever and constitutional symptoms - suggests infectious/inflammatory process 1
• Pain migration pattern - classic appendicitis presents with periumbilical pain migrating to RLQ, though only 50% follow this pattern 1, 2

Imaging Strategy

Primary Recommendation: CT Abdomen and Pelvis with IV Contrast

CT with IV contrast (without oral contrast) is rated 8/9 ("usually appropriate") by ACR guidelines for RLQ pain with suspected appendicitis and is the gold standard for this clinical scenario. 1

Diagnostic performance:

• Sensitivity: 85.7-100% 1, 2
• Specificity: 94.8-100% 1, 2
• Negative appendectomy rate with preoperative CT: 1.7-7.7% (compared to 16.7% with clinical evaluation alone) 1

Key advantages in this age group:

• Evaluates the entire differential diagnosis - can identify appendicitis, diverticulitis, bowel obstruction, malignancy, and other pathology in a single study 1
• Rapid acquisition and interpretation - critical for timely surgical decision-making 1
• Superior to ultrasound in adults - particularly in patients with increased body habitus or bowel gas 1
• Oral contrast is not necessary - avoids delays in diagnosis and treatment without compromising accuracy 1, 2

Alternative Imaging Considerations

Ultrasound is rated 6/9 ("may be appropriate") for RLQ pain but has significant limitations in adults:

• Variable sensitivity (51.8-81.7%) and specificity (53.9-81.4%) for appendicitis 1, 2
• Appendix not visualized in 27-45% of cases 1
• Operator-dependent and limited by body habitus and bowel gas 1
• May miss alternative diagnoses that CT would identify 1

MRI without and with contrast is rated 5/9 ("may be appropriate"):

• Excellent sensitivity and specificity (96-97% and 95%) for appendicitis 1, 2
• Primary role is in pregnant patients to avoid radiation 1, 2
• Limited availability and higher cost restrict routine use 1

Plain radiography is rated 4/9 ("may be appropriate") and has very limited utility:

• Low sensitivity for sources of abdominal pain 1
• May be useful only if perforation with free air is suspected 1
• Results rarely change management 1

Management Algorithm

1. Obtain focused history - prior surgeries, bowel function, constitutional symptoms, pain characteristics 1, 2

2. Physical examination - assess for peritoneal signs, localized tenderness, fever 1, 2

3. Laboratory testing - complete blood count and basic metabolic panel, though normal values do not exclude serious pathology in elderly patients 1

4. Order CT abdomen and pelvis with IV contrast (without oral contrast) as first-line imaging 1, 2

5. Surgical consultation based on imaging findings:

   • Appendicitis - proceed to appendectomy or consider interval appendectomy if abscess present 1
   • Bowel obstruction - surgical evaluation for operative versus conservative management 1
   • Malignancy - staging and oncologic consultation 1
   • Diverticulitis or other inflammatory conditions - medical management versus surgical intervention based on severity 1

Critical Pitfalls to Avoid

• Do not rely on clinical scoring systems alone - the classic appendicitis presentation occurs in only ~50% of cases, and clinical evaluation alone results in higher negative appendectomy rates 1, 2

• Do not delay imaging for oral contrast administration - CT without oral contrast has equivalent diagnostic accuracy and avoids treatment delays 1, 2

• Do not assume normal laboratory values exclude serious pathology - elderly patients may have normal white blood cell counts despite serious infection 1

• Do not use ultrasound as definitive imaging in adults - high nonvisualization rates and operator dependence make it unreliable as a standalone test in this population 1

• Consider malignancy in this age group - colorectal cancer accounts for 60% of large bowel obstructions and should remain high on the differential 1