Abstract
Summary In 6 adult patients without hematologic or hepatic abnormality the efficiency of conversion of bilirubin to colorimetrically measurable fecal urobilinogen, assuming a daily catabolism of 6.25 g of hemoglobin, averaged only 26%. However, the efficiency of conversion of from 8.3 to 11.75 g of hemoglobin subsequently given by slow intravenous infusion averaged 96%. It is suggested that some physiological, biochemical or artifactual process normally diverts a more or less constant amount of bilirubin from conversion to fecal urobilinogen measurable by Ehrlich's aldehyde reagent in collected stools even when the bilirubin to be converted is significantly augmented.