Electrolyte and Osmolality Panel, Feces
Use
The Electrolyte and Osmolality Panel for feces is useful in the workup for chronic diarrhea and the diagnosis of factitious diarrhea where water is deliberately added to stool. The test measures levels of electrolytes and osmolality to identify osmotic and non-osmotic causes of diarrhea. Osmotic diarrhea can result from the ingestion of poorly absorbed ions or sugars, while non-osmotic diarrhea, including secretory diarrhea, results from disruptions in epithelial electrolyte transport. This panel is critical for differentiating between these causes through measurements of sodium, chloride, and calculated osmotic gap among other parameters.
Special Instructions
The test is only clinically valid when performed on watery specimens. Formed fecal samples will lead to test cancellation. Collect a very liquid, random stool specimen and ensure no preservatives are added. Use stool containers provided in the Stool containers-24, 48, 72 Hour Kit. A random but very liquid stool sample is required, collected in a stool container without preservatives. Complete and send a Renal Diagnostics Test Request form if not ordering electronically.
Limitations
The test will not be performed on formed fecal specimens and should not have any preservatives added, as this may lead to specimen rejection. Conditions causing diagnostic confusion include incorrect specimen storage leading to increased osmolality and rare cases of gammopathy affecting results. Phospholipids from certain medications may elevate phosphate results, and perchlorate anions can interfere with chloride readings. Chronic intestinal inflammation and certain medications can also falsely affect results.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 88697-8
- 15207-4
- 15202-5
- 15158-9
- 29911-5
- 73571-2
- 88713-3
- 2693-0
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Stool
Volume
10 g
Minimum Volume
5 g
Container
Stool container
Collection Instructions
Collect a very liquid, random stool specimen. Do not add preservative to the specimen. If a preservative is added, testing will be canceled.
Patient Preparation
No barium, laxatives, or enemas may be used for 96 hours prior to start of, or during, collection.
Causes for Rejection
Preservatives added
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 7 days |
| Frozen | 14 days |