This is a non-invasive test of pancreatic exocrine function. It depends on the hydrolysis of fluorescein dilaurate by cholesterol ester hydrolase, an enzyme normally present in pancreatic juice. Fluorescein is water soluble. It is absorbed by the intestine, conjugated in the liver, and excreted in the urine where it's fluorescence can be measured.
On day one, a tablet containing fluorescein dilaurate is taken and urine collected for 10 hours. On day two, the same procedure is repeated but this time using a tablet containing the equivalent dose of free fluorescein. This allows for correction in individual variations in intestinal, hepatic and renal function.
Results are expressed as the ratio of fluorescein excreted after fluorescein dilaurate and after free fluorescein. A ratio of less than 20% is considered abnormal.
Last reviewed 01/2018