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Alpha-1 Antitrypsin, 72-Hour Stool — Mass Concentration

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

This test measures alpha-1 antitrypsin in stool collected over 72 hours. It may help evaluate protein loss through the digestive tract.

Quick summary

["An elevated stool result can support evaluation for gastrointestinal protein loss, especially when interpreted with other findings."]

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

Key facts at a glance

LOINC
46431-3
Short code
A1AT 72h Stl-mCnt
Synonyms
A1AT 72h Stl-mCnt
Category
liver
Sample
stool
Container
Clean container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

What is this test?

Alpha-1 antitrypsin is a protein made by the liver. This test measures the amount of this protein in a stool sample collected for 72 hours. Stool alpha-1 antitrypsin testing may be used as part of an evaluation for protein-losing enteropathy, a condition in which the digestive tract loses too much protein.

Why might I need this test?

Your clinician may order this test if you have unexplained low blood protein, swelling, or symptoms suggesting that protein is being lost through the intestines. Results are interpreted alongside blood tests, symptoms, and sometimes tests of the stomach or intestines.

How is the test performed?

You collect all stool produced during a 72-hour period into the container provided by the laboratory. The laboratory then measures the alpha-1 antitrypsin concentration in the collected specimen and may report the amount per unit of stool or the total amount collected.

How do I prepare for the test?

Follow the laboratory's collection instructions and record when the collection begins and ends. Do not use a container that is not provided for the test, and tell the laboratory if any stool is missed. Ask your clinician whether fasting or changes to medicines are needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Alpha-1 Antitrypsin Stool Test

Frequently asked questions

Is this the same as an alpha-1 antitrypsin blood test?
No. This test measures alpha-1 antitrypsin in stool, while a blood alpha-1 antitrypsin test measures the protein in the bloodstream and may also assess a deficiency genotype.
Why does the stool collection last 72 hours?
Collecting over 72 hours helps provide a more representative measurement and may allow the laboratory to calculate the total amount excreted. Follow the exact timing and container instructions supplied by the laboratory.
Does an abnormal result confirm protein-losing enteropathy?
No. An elevated result may support the evaluation, but diagnosis usually requires symptoms, blood findings, and sometimes additional gastrointestinal testing. Your clinician will explain what the result means in your situation.
  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