Days Set Up
Tuesday, Thursday
Analytic Time

3 - 10 days

Soft Order Code

Test Updated:


d-Xylose Absorption Test
Xylose Tolerance Test

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Find a Requisition

All specimens should be accompanied by a requisition.

Submitting Specimens

Learn about how to properly label and where to ship specimens.

Order Kits and Supplies

MLabs provides all the supplies necessary for the collection of specimens.

Test FAQ

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Test Overview

Test Methodology


Test Usage

Evaluate mucosal absorption efficiency in a variety of malabsorptive diseases. May be used for diagnosing cause of malabsorption.

Reference Range

Age and dose specific reference ranges provided with report.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Offsite

MLabs does not provide d-xylose; client or physician will need to obtain d-xylose from a local pharmacy. 1) Patient should fast for 8 hours (minimum 4 hours) prior to administration of d-xylose. 2) Prior to administration of d-xylose, have patient empty bladder and discard urine. Collect a blood specimen in a red top tube from the fasting patient. 3) Dissolve 25 grams of d-xylose in 250 mL of water and administer, and follow immediately with an additional 250 mL of water. For patients who do not tolerate the 25 g dose, a 5 g dose can be used. For children aged

Normal Volume
0.5 mL serum (pre- and post-dose) and 5 mL aliquot of 5 hour urine collection
Minimum Volume
0.5 mL serum (pre- and post-dose) and 3 mL aliquot of 5 hour urine collection

Billing Information

CPT Code
Pro Fee Code
3134-4 Blood, 3135-1 Urine

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.