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Test Code 7917 Electrolytes, Feces

Performing Laboratory

Barnes-Jewish Hospital Laboratory


Colorimetric/Direct Ion-Selective Electrode (ISE)/Freezing Point Depression

Includes chloride, magnesium, osmolality, potassium, and sodium.

Specimen Requirements

Specimen Type: Feces, 24-, 48-, or 72-hour

Container/Tube: Specimen container

Specimen Volume: Entire collection

Collection Instructions: Specimen must be liquid.

Additional Information: Length of collection period is required.

Day(s) Test Set Up

Monday through Sunday
Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: 2 to 4 hours after receipt in laboratory

Reference Values

No established reference intervals

Test Classification and CPT Coding





Additional Information

For BJH Laboratory Use Only
Analyte Stability:

Not established; performed upon receipt

Laboratory Processing Instructions:

Test performed in BJH Core Lab. Document volume and period. Using 16x20 glass tubes, prepare a 10-mL aliquot tube and centrifuge. Supernatant must be fluid and non-viscous. Deliver to the Cobas 8000. Program the specimen as urine and analyze the supernatant. Completed specimens are stored refrigerated for 5 days. 

Specimen Transport Temperature

Ambient/Refrigerate NO/Frozen NO

LOINC Code Information

Name LOINC Code
Chloride in stool 15158-9
Magnesium per 24 hour stool 29912-3
Sodium in stool 15207-4
Osmolality fecal 2693-0
Potassium in stool 15205-5