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Entamoeba histolytica stool antigen detection by probe

Published: August 9, 2026Updated: August 17, 2026

This test checks for the presence of *Entamoeba histolytica* antigens in your stool, a parasite that can cause intestinal infections.

Quick summary

["A positive result may indicate an infection requiring medical evaluation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
103660-7
Short code
Entamoeba coli DNA Stl Ql NAA+probe
Synonyms
Entamoeba coli DNA Stl Ql NAA+probe
Category
chemistry
Sample
stool
Container
Clean container
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
CPT
84484
SNOMED
302774002
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have symptoms like diarrhea, abdominal pain, or blood in your stool, or if you’ve traveled to areas with higher parasite risks. It helps confirm whether *Entamoeba histolytica*—a type of amoeba—is causing an infection in your digestive system.

What to Expect Before the Test

No special preparation is needed. Bring a fresh stool sample to the lab. If you’re using a collection kit, follow the instructions carefully to ensure accuracy.

What the Test Measures

The test detects specific antigens (proteins) from *Entamoeba histolytica* in your stool. These antigens are released when the parasite is active, helping doctors diagnose infection without needing a microscopic stool exam.

Possible Results and Next Steps

A **positive result** suggests an active infection and may prompt treatment with antiparasitic medications. A **negative result** means no detectable antigens, but other causes of symptoms (like food poisoning or IBS) could still be present. Follow-up testing or a doctor’s guidance may be needed.

Reference range

Adult: 10-40 U/LN/A

Specimen: stool

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Entamoeba stool test

Frequently asked questions

What does a positive result mean?
A positive result strongly suggests an *Entamoeba histolytica* infection, which can cause amoebic dysentery (severe diarrhea with blood) or liver abscesses in some cases. Early treatment is important to prevent complications.
Could this test miss an infection?
Yes, if the infection is mild or recent, the test may not detect antigens. Microscopic stool exams or other tests (like bloodwork) might be needed for confirmation.
How long does it take to get results?
Results are typically available within 24–48 hours, depending on lab processing times. Your doctor will discuss the findings with you.
  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 17, 2026. · Read our editorial policy