Urobilinogen is a bile pigment that is produced by the degradation of conjugated bilirubin in the biliary tree and small intestine. It is water soluble and colourless.
Urobilinogen has several fates:
- partial oxidation to urobilin
- partial reabsoption in the small intestine and recirculation back to the liver - enterohepatic circulation
- reabsorption into blood and passage to kidney for excretion
Hence, urobilinogen is present in the urine of normal subjects. If there is an increase in urobilinogen in the urine then this indicates hepato-cellular dysfunction or an increased bilirubin formation, e.g. due to haemolysis. In intrahepatic obstruction there is no urobilinogen in the urine.
Last reviewed 01/2018