Results may be used to evaluate deficiency of small bowel mucosal lactase, which may be associated with intolerance to lactose, manifested by diarrhea and other symptoms following ingestion of milk.
Important Note: If patient is to be drawn at Quest Diagnostics PSC,
the test must be scheduled at a PSC capable of administering the dose.
Please call 1-866-MyQuest to schedule. Fasting required. Fasting is
defined as no consumption of food or beverage other than water for at
least 8 hours before testing.
Immediately after a fasting specimen is obtained, have patient ingest
a 50 g dose of lactose (supplied by laboratory). Draw subsequent
specimens 1/2, 1, 2 and 3 hours later. Label each with the specific
Note: Children should receive 1.75g lactose per kg ideal body weight,
up to 50 g.
Reported (Analytical Time)
The CPT codes provided are based on AMA guidelines and are for informational purposes only.
CPT coding is the sole responsibility of the billing party.
Please direct any questions regarding coding to the payer being billed.
Reject Criteria: Unspun serum separator tube; anticoagulants other than lithium or sodium heparin or fluoride/oxalate; red-top or non-plasma separator green-top tubes.
Transport Temperature: Room temperature
Specimen Requirements: Preferred: 1 mL (0.5 mL minimum) plasma collected in each of five fluoride/oxalate (gray-top) tubes
Acceptable Specimens: Lithium or sodium heparin or serum (separated from cells immediately) collected in a plastic screw-cap vials or spun SST