Urobilinogen is a colourless product of bilirubin reduction. It is formed in the intestines by bacterial action. Some urobilinogen is reabsorbed, taken up into the circulation and excreted by the kidney. Most of urobilinogen will be excreted along with feces, and other part will be absorbed by the liver reback to the intestinal, then from the liver enter into the kidney or the blood and excret out together with the urine. There will form Urobilinogen after exposure to the air.
Normal(-)
Mildly Abnormal(+)
Moderately Abnormal(++)
Severely Abnormal(+++)