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Giardia lamblia Antigen in Stool (Qualitative)

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

This test detects the presence of *Giardia lamblia*, a microscopic parasite that can cause intestinal infections, often leading to diarrhea, stomach cramps, or bloating. It helps identify if you’ve been exposed to this parasite.

Quick summary

["A simple stool test to check for a common parasite causing digestive symptoms."]

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

Key facts at a glance

LOINC
9658-6
Short code
G lamblia IgA Ser-aCnc
Synonyms
G lamblia IgA Ser-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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

Why This Test Matters

Giardia is a common parasite found in contaminated water or food. It can spread in places with poor sanitation, like daycare centers, camps, or after travel to areas with unsafe water sources. This test helps doctors diagnose infections early to prevent ongoing discomfort or complications like malnutrition in children.

How the Test Works

The test looks for specific proteins (antigens) produced by *Giardia lamblia* in your stool. If these proteins are found, it suggests you’re infected. The result is either positive (infection present) or negative (no infection detected).

What to Expect Before the Test

No special preparation is needed. You’ll provide a single stool sample in a provided container. If you’re using a home test kit, follow the instructions carefully. If done in a lab, a healthcare provider will collect the sample for you.

What the Results Mean

A **positive result** means the test found evidence of *Giardia lamblia* in your stool, indicating an active infection. A **negative result** means no parasite was detected at the time of testing, but you may still need further testing if symptoms persist. Follow-up may include retesting or additional tests if needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Giardia stool test (qualitative)

Frequently asked questions

What symptoms might this test be used for?
This test is often ordered if you have symptoms like persistent diarrhea, bloating, gas, or stomach cramps that don’t improve with usual treatments. It’s also used in travelers, children with frequent diarrhea, or people in areas with known parasite risks.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on the lab. Home test kits may provide results immediately or within a few hours.
Can I have this test if I’m pregnant?
Yes, this test is safe during pregnancy. It doesn’t expose you to harmful substances and helps ensure proper care for you and your baby if needed.
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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