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Giardia duodenalis (Giardia lamblia) antigen in stool

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

This test detects the presence of Giardia duodenalis, a microscopic parasite that can cause intestinal infections. It helps identify if you have an infection caused by this parasite.

Quick summary

["This test checks for Giardia, a common intestinal parasite that may cause symptoms like stomach cramps, diarrhea, or bloating."]

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

Key facts at a glance

LOINC
88161-5
Short code
T gondii Ocflu Ql Cult
Synonyms
T gondii Ocflu Ql Cult
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
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 Is Done

Your healthcare provider may recommend this test if you have symptoms like persistent diarrhea, stomach pain, bloating, or gas that don’t improve with usual treatments. It’s also used in people who travel to areas with higher parasite risks or those with weakened immune systems.

How the Test Works

A small sample of your stool is collected and tested to detect specific antigens (proteins) from Giardia. This method is quick and doesn’t require special preparation.

Sample Collection

You’ll need to provide a fresh stool sample, often collected in a special container provided by your lab. Multiple samples may be needed for accurate results.

What to Expect

The test is usually done in a lab setting and doesn’t require any special preparation. Results are typically available within a few days.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Giardia infections can lead to chronic diarrhea, malnutrition, and dehydration, especially in children or those with compromised immune systems. Early detection allows for prompt treatment with medications like metronidazole or tinidazole to clear the parasite and relieve symptoms.

Short name

Giardia stool test

Frequently asked questions

How long does it take to get the results?
Results are usually available within 2 to 5 business days, depending on your lab’s processing schedule. Your healthcare provider will contact you once they have the results.
What are common symptoms of Giardia infection?
Common symptoms include watery diarrhea, stomach cramps, bloating, gas, nausea, and sometimes a foul-smelling stool. Some people may not have any symptoms at all.
Can Giardia be spread through food?
Yes, Giardia can be spread through contaminated food or water. It’s important to avoid raw fruits and vegetables washed in potentially unsafe water, and to ensure proper food handling and hygiene to prevent infection.
  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