Giardia duodenalis Antigen in Stool by Immunoassay (Qualitative)
This test detects the presence of Giardia duodenalis, a microscopic parasite that can cause intestinal infections, often leading to symptoms like diarrhea, stomach cramps, or bloating.
["A simple stool test to check for Giardia infection, which may cause digestive issues."]
Key facts at a glance
- LOINC
- 91836-7
- Short code
- Giardia DNA Lower resp Ql NAA+probe
- Synonyms
- Giardia DNA Lower resp Ql NAA+probe
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- 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 Might Be Ordered
Your healthcare provider may recommend this test if you’ve experienced persistent diarrhea, abdominal pain, or other gastrointestinal symptoms that could be linked to a parasite infection. It’s also used in cases of travel-related illness, especially if you’ve visited areas with poor sanitation or consumed contaminated water. Additionally, it may be part of routine screening for individuals at higher risk, such as those with weakened immune systems or those in daycare settings.
What to Expect Before the Test
No special preparation is needed for this test. You’ll provide a single stool sample in a provided container. It’s best to collect the sample early in the morning for accuracy, but any time of day is fine. Avoid using toilet paper or cleaning products in the sample, as they can interfere with results.
What to Expect During the Test
The test involves sending your stool sample to a lab, where it will be analyzed using an immunoassay method to detect Giardia antigens. Results are typically available within 24 to 48 hours, depending on lab processing times.
What the Results Mean
A positive result means Giardia antigens were found in your stool, indicating an active infection. A negative result means no detectable antigens were found, but this doesn’t always rule out infection if it was recent or cleared quickly. Follow-up testing or additional symptoms may guide further evaluation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Giardia duodenalis is a common cause of intestinal infections worldwide. Symptoms can range from mild, watery diarrhea to severe dehydration, especially in young children or those with compromised immune systems. Early diagnosis and treatment with appropriate antibiotics can help resolve symptoms and prevent complications. Chronic infection may lead to malnutrition or other long-term digestive issues.
Short name
Giardia Stool Test (Qualitative)
Frequently asked questions
How long does it take to get results from this test?
Can I eat or drink before giving the stool sample?
What if I have multiple bowel movements during the day?
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