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Test Code OSMOF Osmolality, Feces

Reporting Name

Osmolality, F

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Measurement of osmolality for the workup of cases of chronic diarrhea

 

Diagnosis of factitious diarrhea (where patient adds fluid to stool to simulate diarrhea)

Method Name

Freezing Point Depression


Ordering Guidance


This test is only clinically valid if performed on watery specimens. In the event a formed fecal specimen is submitted, the test will not be performed.



Specimen Required


Patient Preparation: No barium, laxatives, or enemas may be used for 96 hours prior to start of, or during, collection.

Supplies: Stool containers - 24, 48, 72 Hour Kit (T291)

Container/Tube: Stool container

Specimen Volume: 10 g

Collection Instructions: Collect a very liquid stool specimen.


Specimen Type

Fecal

Specimen Minimum Volume

5 g

Specimen Stability Information

Specimen Type Temperature Time Special Container
Fecal Frozen (preferred) 14 days
  Refrigerated  7 days
  Ambient  48 hours

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

An interpretive report will be provided

Interpretation

Stool osmolality below 220 mOsm/kg indicates dilution with a hypotonic fluid.(1)

Day(s) Performed

Monday, Thursday

Report Available

1 to 3 days

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

84999

LOINC Code Information

Test ID Test Order Name Order LOINC Value
OSMOF Osmolality, F 2693-0

 

Result ID Test Result Name Result LOINC Value
OSMOF Osmolality, F 2693-0