Stercobilinogen

Stercobilinogen is a precursor of stercobilin. Bilirubin is pigment which results from the breakdown of the heme moiety of hemoglobin. The liver conjugates bilirubin, making it water soluble and the conjugated form is excreted in urine (urobilinogen), giving urine it's colour. In the intestine, bilirubin is converted by bacteria to stercobilinogen (fecal urobilinogen). Stercobilinogen is absorbed and excreted by either the liver or the kidney. Stercobilinogen is oxidised to stercobilin, which is responsible for the pigmentation of feces.

In early liver disease, impaired biliary excretion causes the sterocobinogen to be absorbed mostly by the kidney, and therefore, Stercobilinogen will appear in the urine in excess as urobilinogen. This is a marker of early liver disease.