Urobilinogen

Urobilinogen comes from the transformation of bilirubin, a product of the breakdown of hemoglobin in the red blood cells. Urobilinogen is normally eliminated in the stool after passing through the liver and gallbladder. However, small quantities of urobilinogen are found in normal urine, where they contribute to the typical yellow colour of the specimen. Two situations can lead to an increase in urobilinogen levels in urine: a liver disease that disturbs the normal passage of urobilinogen through the liver and gallbladder (viral hepatitis, cirrhosis of the liver, obstruction of the gallbladder by gallstones, etc.), or a urobilinogen overload caused by the release of larger quantities of hemoglobin (destruction of a abnormally high number of red blood cells as in hemolytic anemia, pernicious anemia, etc.).