Urobilinogen
（重定向自Urobilinuria）
![](/Images/godic/202502/19/Structure_of_urobilinogen3758.png")
Urobilinogen is a colourless by-product of bilirubin reduction. It is formed in the intestines by bacterial action on bilirubin. About half of the urobilinogen formed is reabsorbed and taken up via the portal vein to the liver, enters circulation and is excreted by the kidney.