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d-Xylose, urine, 5 hour

Lab Section:  Sendout Reference  
Lab Location:  Sendout
Reference Lab: Quest 
Test ID: LAB2907 
Synonyms: D-Xylose, Timed Urine
Methodology: Colorimetric
Schedule: Daily
Reported: 5-7 days
Specimen Requirements:  Collection: 10.0 mL Urine in a Gray Top Tube.
Pediatric volume: 5 mL.
Handling: 5-mL aliquot urine in a fluoride oxalate (gray-top) tube after 5 hour collection..
Stability: Ambient: 7 days Refrigerated: 7 days Frozen: 30 days


1. At the start of the test, have the patient empty the bladder completely and discard the urine. Some physicians recommend checking a fasting urine and/or a blood sample for non-specific interferences. If requested, retain an aliquot of the urine and collect a blood specimen at this time. 2. Give 25 grams of D(+)-xylose (or 5 grams if so specified by the physician) dissolved in 250 mL water followed immediately by an additional 250 mL water to ensure a urine flow of at least 60 mL/hour. For children, give 0.5 g xylose/kg of body weight up to 25 g, reducing the amount of water accordingly. 3. Collect all urine specimens voided during the next 5-hour period, including the final 5-hour void in the same container. Keep container refrigerated during collection. 4. Mix total urine collection thoroughly, measure total volume and aliquot. Aliquot urine into an empty gray-top blood collection tube (the oxalate/fluoride will serve as a preservative for the urine). If gray-top tube is glass, please transfer urine to a plastic tube before shipping. 5. Record the dose of Xylose given and the total 5-hour volume of the urine collection. If additional tests are ordered, please submit a separate specimen. Adult patients and children should be kept fasting overnight and during test period (infants are fasted for 4 hours).

Reference Interval:  See patient report or consult reference laboratory website
CPT Code(s): 84620
Last Changed: 10/24/2016 01:49:04
Last Reviewed: 12/21/2016 06:06:05