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Colon Fluid, 2-Hour Specimen — Osmolality and Protein Concentration

Published: August 9, 2026Updated: August 16, 2026

A specialized analysis of fluid collected from the colon to measure dissolved-particle concentration (osmolality) and the amount of protein.

Quick summary

["This test helps evaluate the composition of colon fluid but must be interpreted alongside the collection method and clinical findings."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
42013-3
Short code
Deprecated Colon Flr W H2O sol contr PR
Synonyms
Deprecated Colon Flr W H2O sol contr PR
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr-fluor
CPT
86592
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test analyzes fluid collected from the colon. Osmolality measures the concentration of dissolved particles, while the protein measurement estimates how much protein is present in the fluid.

Why might I need this test?

It may be used in specialized evaluations of intestinal inflammation, fluid handling, or changes in the intestinal lining. It is not a routine screening test and is usually interpreted by a clinician familiar with the collection procedure.

How is the test performed?

A healthcare professional collects colon fluid during a clinical procedure. The laboratory measures the fluid's osmolality and protein concentration using validated laboratory methods.

How do I prepare for the test?

Preparation depends on the procedure used to collect the fluid. Follow your clinician's instructions regarding bowel preparation, laxatives, enemas, diet, and medications, and do not use these products unless specifically directed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Colon fluid osmolality and protein

Frequently asked questions

Is this the same as a stool test?
No. This test analyzes fluid directly collected from the colon rather than a stool sample.
Does a high osmolality mean I am dehydrated?
Not necessarily. It describes the concentration of particles in the collected colon fluid and can also be influenced by intestinal processes and collection conditions.
Why is my healthcare provider checking protein in colon fluid?
Protein may be measured to evaluate inflammation or leakage from the intestinal lining. The finding is nonspecific and is interpreted together with the rest of the clinical evaluation.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy