Urobilinogen bodies are derivatives of bilirubin . There are several urobilinogen bodies (urobilinogen, sterkobilinogen) and urobilin bodies (urobilin, sterkobilin). Since it is difficult to separate urobilinogen and stercobilinogen analytically, the name urobilinogen is used for both substances.
Bilirubin is mainly excreted with excrement , but is first processed by the intestinal flora. Bilirubin passes into urobilinogen partly already in the gallbladder , but the process finally takes place in the colon with the help of the intestinal flora. Bacterial enzymes process the bilirubin pigment into urobilinogen bodies (colorless compounds of mesobilinogen - urobilinogen and sterkobilinogen (L-urobilinogen)).