Protocol

The patient should be fasted overnight and should empty their bladder before the test.

At t=0:

• give 5 g xylose orally, dissolved in water
• collect all urine for the next 5 hr
• patient should drink 500 ml of water over the next 2 hr

At t=1 hr:

• draw blood and determine concentration of xylose

At t=5 hr:

• finish urine collection
• analyse urine for xylose

Normal results are:

• serum xylose concentration at 1 hr in excess of 1.3 mM
• urinary xylose excretion in excess of 7.0 mmol/5 hr