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Chloridegastscnc

Published: July 31, 2026Updated: August 17, 2026

A test that measures chloride levels in stomach fluid to evaluate digestive function and diagnose certain gastrointestinal conditions.

Quick summary

{"Measures chloride concentration in stomach fluid","Helps diagnose conditions affecting stomach acid production","Collected via gastric aspiration during endoscopy or tube placement","Abnormal results may indicate digestive disorders","Results help guide treatment for acid-related conditions"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
59178-4
Short code
CLGAST
Synonyms
Chloride Gast-sCnc
Category
electrolyte
Sample
serum
Container
Sterile plastic container or sterile specimen cup. Avoid glass containers that may adsorb chloride ions.
Units
not specified
Ref low
100
Ref high
150
Critical range
— – 500 not specified
Fasting
false
Population
adult
Sex
all
Age range
≥ 18 years
Method
Ion-selective electrode (ISE) method or coulometric titration
CPT
82436 (Chloride, blood) - may require modifier for gastric fluid
SNOMED
314255001
Specimen volume
1-5 mL of gastric fluid is typically sufficient for analysis.
Stability
Room temperature: 24 hours. Refrigerated (2-8°C): 72 hours. Freeze at -20°C for longer storage.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
2–24 hours
Order
routine

What is this test?

The Gastric Fluid Chloride test measures the amount of chloride, an important electrolyte, in the fluid collected from your stomach. Chloride is a component of stomach acid (hydrochloric acid) and plays a key role in proper digestion. This test helps doctors evaluate how well your stomach is producing acid and functioning.

How is the sample collected?

Gastric fluid is typically collected through a thin tube (nasogastric or orogastric tube) that is passed through the nose or mouth into the stomach. The procedure is usually done during an endoscopy or as a separate test called gastric aspiration. The fluid is then sent to a laboratory for analysis.

Why is this test performed?

Your doctor may order this test to: evaluate symptoms like persistent heartburn, acid reflux, or unexplained vomiting; diagnose conditions like Zollinger-Ellison syndrome (which causes excess stomach acid production); assess gastric function after surgery; or investigate suspected gastric outlet obstruction. It may also be used in evaluating cystic fibrosis or certain congenital disorders in infants.

What do the results mean?

Normal gastric fluid chloride levels typically range from 20-60 mEq/L, though ranges may vary by laboratory. Higher than normal levels may indicate increased stomach acid production (hyperchlorhydria). Lower than normal levels may suggest reduced stomach acid (hypochlorhydria), gastric atrophy, or certain types of anemia. Your doctor will interpret your results based on your specific clinical situation.

Reference range

100-150 mmol/Lnot specified

Specimen: serum

Overnight fasting required; discontinue antacids/H2-blockers/PPIs; collected via nasogastric tube

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is the test painful?
You may experience some discomfort when the tube is inserted through your nose or throat. The procedure is generally well-tolerated and only takes a few minutes. Your healthcare provider may use a numbing spray to make the process more comfortable.
Do I need to fast before the test?
Typically, you will be asked to fast for 8-12 hours before the test to ensure an empty stomach. Your doctor will provide specific instructions based on your situation. It is important to follow these instructions for accurate results.
How long does it take to get results?
Results are usually available within 1-3 days, depending on the laboratory. Your doctor will discuss the results with you during a follow-up appointment.
Are there any risks or side effects?
The procedure is generally safe. Possible minor risks include mild sore throat, nosebleed, or slight gagging during tube insertion. Serious complications are rare but may include perforation (tear) of the stomach or esophagus, which is very uncommon.
What happens if my results are abnormal?
An abnormal result does not necessarily mean you have a serious condition. Your doctor will consider your symptoms, medical history, and other test results to determine the cause. Additional testing may be needed to confirm a diagnosis and guide treatment.
  1. 1
    MedlinePlus - Gastric fluid analysisSource
  2. 2
    Mayo Clinic Laboratories - Test CatalogSource
  3. 3
    LOINC - Chloride [Moles/volume] in Gastric fluidSource

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 17, 2026. · Read our editorial policy