The elevated urine bilirubin levels with no increase in urobilinogen levels, amber urine, and clay colored stool all point to posthepatic jaundice. This condition results from an obstruction in the path of the conjugated bilirubin after it leaves the liver. The liver is healthy, but something is preventing the bilirubin from entering the intestines. It becomes backed up in the liver, eventually overflowing into systemic circulation where it is cleared by the kidneys. An increase of bilirubin is ultimately found in the urine, causing the amber color that was seen.
    Conjugated bilirubin is converted into urobilinogen in the intestine. In posthepatic jaundice, bilirubin does not reach the intestines so urobilinogen cannot be formed. The formation of urobilinogen by the intestines results in a brown fecal color. Clay colored stools indicate an absence of urobilinogen.
    A yellow tint of the skin is caused by an excess of bilirubin in the body because it is highly pigmented. Jaundice is the term applied to this condition.