Laboratory Workup for Right Upper Quadrant Pain with Orange Diarrhea
Order a comprehensive hepatobiliary panel immediately, including complete blood count, liver function tests (ALT, AST, alkaline phosphatase, GGT, total and direct bilirubin), amylase, lipase, and a pregnancy test if the patient is a woman of reproductive age. 1
Essential First-Line Laboratory Tests
The combination of RUQ pain with "orange" symptoms (suggesting jaundice/icterus) and diarrhea raises concern for biliary obstruction, cholangitis, or hepatobiliary disease requiring urgent evaluation:
- Complete Blood Count (CBC): Assess for leukocytosis with left shift, which indicates infection or inflammation such as acute cholecystitis or cholangitis 1
- Comprehensive Liver Function Tests: Include ALT, AST, alkaline phosphatase, GGT, and both total and direct bilirubin to evaluate for hepatobiliary disease and distinguish cholestatic from hepatocellular patterns 1
- Pancreatic Enzymes: Amylase and lipase to rule out pancreatitis, which commonly presents with RUQ pain and can cause biliary obstruction 1
- Pregnancy Test: Mandatory for all women of reproductive age to exclude ectopic pregnancy before any imaging 2, 1
Critical Clinical Context
The "orange" appearance you describe likely represents jaundice or icterus, which combined with RUQ pain and systemic symptoms creates concern for:
- Acute Cholangitis: Requires the triad of jaundice, fever/chills, and RUQ pain plus laboratory evidence of biliary stasis 2. Elevated bilirubin with cholestatic liver enzyme pattern (elevated alkaline phosphatase and GGT disproportionate to transaminases) strongly suggests biliary obstruction 1
- Choledocholithiasis: Common bile duct stones causing obstruction manifest with elevated liver enzymes and jaundice 2
Additional Tests Based on Clinical Severity
- Coagulation Studies (PT/INR): If severe liver dysfunction or bleeding risk is suspected based on clinical presentation 3
- Lactate Level: If the patient appears septic or you suspect mesenteric ischemia or severe cholangitis 3
- Blood Cultures: If fever is present, obtain before starting antibiotics for suspected cholangitis 2
Immediate Next Steps After Laboratory Results
Do not delay ultrasound imaging while waiting for laboratory results. Ultrasound is the first-line diagnostic test rated 9/9 (usually appropriate) by the American College of Radiology for RUQ pain evaluation 2, 1. The presence of jaundice ("orange" appearance) with RUQ pain mandates urgent imaging to assess for:
- Gallbladder wall thickening, pericholecystic fluid, and gallstones 1
- Bile duct dilatation suggesting obstruction 2
- Sonographic Murphy's sign 1
Critical Pitfalls to Avoid
- Never assume normal labs exclude serious pathology: Normal laboratory values do not exclude conditions requiring imaging, particularly if clinical suspicion remains high 3
- Do not skip the pregnancy test: Failing to order this in women of reproductive age risks missing ectopic pregnancy, a life-threatening condition 2, 3
- Recognize cholangitis urgency: If labs show leukocytosis with elevated bilirubin and cholestatic enzymes, this patient needs immediate referral to the emergency department or acute surgical service for suspected acute cholangitis 2
When to Escalate Imaging
If ultrasound is equivocal but clinical suspicion remains high (persistent jaundice, fever, elevated cholestatic enzymes), proceed immediately to:
- MRCP: 85-100% sensitivity for cholelithiasis/choledocholithiasis, superior to CT for biliary pathology 4, 2
- CT with IV contrast: If complications like perforation, abscess, or gangrenous cholecystitis are suspected 2
The combination of jaundice ("orange"), RUQ pain, and systemic symptoms represents a potentially urgent biliary emergency until proven otherwise.