1. Mesobilirubinogen, urobilinogen, and urobilin represent intestinal breakdown products of bilirubin catabolism. 220.

2. This circulating urobilinogen is almost completely picked up by the liver with only a small amount excreted in the urine.

3. Urobilinogen reflect a more sensitive liver function.

4. However, the lack of bile flow into the intestines will result in neither urobilinogen nor urobilin being found in the feces.

5. The liver oxidizes a small part of the recycled urobilinogen to bilirubin.