Alpha-1 Antitrypsin, 24-Hour Stool — Mass Rate
Measures the amount of alpha-1 antitrypsin lost in stool over 24 hours to help evaluate protein loss through the digestive tract.
["This 24-hour stool test can help identify excess gastrointestinal protein loss when low blood protein levels or related symptoms are present."]
Key facts at a glance
- LOINC
- 74990-3
- Short code
- A1AT 24h Stl-mRate
- Synonyms
- A1AT 24h Stl-mRate
- 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?
This test measures alpha-1 antitrypsin, a protein, in all of the stool collected over 24 hours. The result estimates the amount of this protein lost through the digestive tract each day.
Why might I need this test?
It may be ordered if you have low blood protein levels, swelling, or other findings that suggest protein is being lost through the intestines. It can also help evaluate unexplained low albumin in certain people with liver or gastrointestinal conditions.
How is the test performed?
You collect all stool for a full 24 hours using the container and instructions supplied by the laboratory or your healthcare provider. The laboratory measures the alpha-1 antitrypsin in the collected sample and reports the daily amount or rate.
How do I prepare for the test?
Fasting is usually not required, but you should follow the collection instructions exactly and record when the collection begins and ends. Tell your healthcare provider about medicines or antibiotic use, because they may affect the interpretation, and do not change medicines unless instructed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An increased amount of alpha-1 antitrypsin in 24-hour stool may indicate abnormal loss of protein into the digestive tract, a condition sometimes called protein-losing enteropathy. Results must be interpreted with blood alpha-1 antitrypsin and albumin levels, stool amount, symptoms, and other findings. A lower-than-expected result does not completely rule out protein loss, particularly if collection was incomplete or the person had intestinal inflammation.
Short name
24-Hour Stool Alpha-1 Antitrypsin
Frequently asked questions
Does this test require a blood sample?
Why is stool collected for 24 hours?
What should I do if I miss part of the collection?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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