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Alpha-1 Antitrypsin, 48-Hour Stool Collection — Mass Concentration

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

Measures alpha-1 antitrypsin in stool collected over 48 hours to help evaluate gastrointestinal protein loss.

Quick summary

["This test can help determine whether protein is being lost through the digestive tract."]

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

Key facts at a glance

LOINC
46430-5
Short code
A1AT 48h Stl-mCnt
Synonyms
A1AT 48h Stl-mCnt
Category
liver
Sample
stool
Container
Clean container
Units
N/A
Ref low
4.5
Ref high
12
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84436
SNOMED
302345006
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

What is this test?

This test measures the concentration of alpha-1 antitrypsin, a protein, in stool collected for 48 hours. It may be used to investigate gastrointestinal protein loss, particularly when other findings suggest a protein-losing intestinal disorder.

Why might I need this test?

Your clinician may order this test if you have persistent diarrhea, swelling, unexplained weight loss, low blood protein, or other signs that protein may be leaking into the digestive tract. It may also help evaluate conditions affecting the stomach or intestines.

How is the test performed?

You collect all stool during a 48-hour period in the container provided by the laboratory. The laboratory then measures the alpha-1 antitrypsin concentration in the collected specimen, and your clinician interprets it along with your symptoms and other test results.

How do I prepare for the test?

Follow the laboratory's collection instructions carefully, and do not place stool directly into toilet water or mix it with urine or cleaning products. Keep the container tightly closed and refrigerated if instructed, and tell your clinician about diarrhea, bowel bleeding, or major changes in stool volume.

Reference range

Adult: 4.5-12.0 μg/dLN/A

Specimen: stool

Take your thyroid medication after the blood draw if applicable. No fasting required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

48-Hour Stool Alpha-1 Antitrypsin

Frequently asked questions

Does this test diagnose alpha-1 antitrypsin deficiency?
No. This test evaluates alpha-1 antitrypsin lost into the stool. Diagnosis of alpha-1 antitrypsin deficiency usually relies on blood testing and, when needed, genetic testing.
Why is a 48-hour stool collection needed?
A timed collection helps the laboratory measure alpha-1 antitrypsin across a full bowel movement cycle. Collecting all stool consistently improves the accuracy and interpretation of the result.
What symptoms may lead to this test being ordered?
Common reasons include persistent diarrhea, swelling, low blood protein, unexplained weight loss, or symptoms of stomach or intestinal disease. Your clinician determines whether this test is appropriate based on your medical history and other findings.
  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