Urobilinogen
Overview
Urobilinogen measures colorless tetrapyrrole compound formed in the distal gut by bacterial reduction of bilirubin and partially reabsorbed into portal circulation for hepatic re-excretion. It serves as a marker of hepatic bilirubin metabolism and enterohepatic circulation integrity. Elevated urinary levels indicate hepatic dysfunction, hemolytic disorders, or biliary obstruction, while absent levels suggest complete biliary obstruction; clinically useful for screening hepatobiliary disease, differentiating conjugated from unconjugated hyperbilirubinemia, and evaluating liver synthetic function.Clinical Use Cases
- Screening for hepatocellular disease and cholestasis.
- Evaluating hemolytic anemia with increased bilirubin load.
- Differentiating obstructive jaundice from hepatocellular jaundice.
- Monitoring liver transplant function.
- Assessing drug-induced hepatotoxicity.
Specimen Types
- Random urine.
- 24-hour urine collection.
Measurement Methods
- Dipstick Ehrlich reaction (p-dimethylaminobenzaldehyde).
- Watson-Schwartz qualitative test.
- Spectrophotometric quantification.
Test Preparation and Influencing Factors
- Avoid antibiotics (alter gut flora reducing urobilinogen).
- Recent barium studies interfere with dipstick.
- Exposure to light degrades samples.
- Sulfonamides, methyldopa cause false-positive Ehrlich reaction.
- Collect midstream clean-catch urine.
Synonyms
- URO.
- Urine urobilinogen.