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22915 Osmolality, Stool

Osmolality, Stool
Test Code: OS-O
Synonyms/Keywords
Fecal Osmo​
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Stool​ Sage Container​ ​ 10 mL​ 0.3 mL​ 0.2 mL liquid supernatant​
Collection Processing Instructions
Collect liquid stool or any specimen other than serum or urine. Collect specimen without preservative. Stool specimen must be weighed before it is given to Clinical Microscopic for analysis. Indicate collection time.​
Specimen Stability Information
Specimen Type Temperature Time
Stool​ Refrigerated​ 48 hours​
Frozen​ >48 hours​
Rejection Criteria
Formed stool
Stool with insufficient liquid​
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Eau Claire​​Monday through Sunday​​​Less than 2 hours​​Freezing Point Depression​
Flambeau Hospital​ ​Monday through Sunday​ ​Less than 2 hours​ ​Freezing Point Depression​
Marshfield​ Monday through Sunday​ Less than 2 hours​ Freezing Point Depression​
Neillsville​Monday through Sunday​​Less than 2 hours​Freezing Point Depression​
Test Information
If stool specimen for Fecal Fat is also ordered, specimen must be kept refrigerated or on ice during collection and transport. Gap calculation= Osmolality - 2(Na + K).​
Reference Range Information
Performing Location Reference Range
All Performing Sites For diarrheal stools:
Gap >100: Consistent with osmotic diarrhea.
Gap 40 - 100: Non-diagnostic. Gap <40: Consistent with secretory diarrhea.​
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
83930 ​ ​ ​ ​ ​
Synonyms/Keywords
Fecal Osmo​
Ordering Applications
Ordering Application Description
​Centricity ​Osmolality
​Cerner ​Osmolality Other
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
Stool​ Sage Container​ ​ 10 mL​ 0.3 mL​ 0.2 mL liquid supernatant​
Collection Processing
Collect liquid stool or any specimen other than serum or urine. Collect specimen without preservative. Stool specimen must be weighed before it is given to Clinical Microscopic for analysis. Indicate collection time.​
Specimen Stability Information
Specimen Type Temperature Time
Stool​ Refrigerated​ 48 hours​
Frozen​ >48 hours​
Rejection Criteria
Formed stool
Stool with insufficient liquid​
Reference Range Information
Performing Location Reference Range
All Performing Sites For diarrheal stools:
Gap >100: Consistent with osmotic diarrhea.
Gap 40 - 100: Non-diagnostic. Gap <40: Consistent with secretory diarrhea.​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Eau Claire​​Monday through Sunday​​​Less than 2 hours​​Freezing Point Depression​
Flambeau Hospital​ ​Monday through Sunday​ ​Less than 2 hours​ ​Freezing Point Depression​
Marshfield​ Monday through Sunday​ Less than 2 hours​ Freezing Point Depression​
Neillsville​Monday through Sunday​​Less than 2 hours​Freezing Point Depression​
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
83930 ​ ​ ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.