Ova and Parasite Test
Reviewed
Also called: parasitic examination (stool), stool sample exam, stool O&P, fecal smear, egg cyst
An ova and parasite test looks for intestinal parasites and their eggs (ova) by checking a sample of your stool (poop) under a microscope.
Specimen: stool (feces)
Why this test may be ordered
- Persistent diarrhea, abdominal pain, gas, nausea, vomiting, or fever
- Blood or mucus in stool, greasy or foul-smelling stools
- Suspected exposure to parasites (e.g., contaminated water, travel, contact with infected person)
- Weakened immune system, very young or older age
Preparation and collection
You don't need any special preparations for an ova and parasite test.
You will need to provide a stool sample for your test. There are different ways to collect stool samples so follow the instructions carefully. Make sure the stool doesn't mix with any urine, toilet paper, or water from the toilet. To get accurate test results, you may need to collect several stool samples over a few days. That's because parasites may not show up in your stool every day.
There is no known risk to having an ova and parasite test.
Understanding results
Testing several samples will increase the chance that the parasites will be found.
- Negative (normal): A negative or normal test result means that no parasites or eggs were found in your stool sample. Limitation: This may mean: You don't have parasites. There were not enough parasites in your sample to show up in a test. Next step: Your provider may order another test and/or different tests to help find out what's causing your symptoms.
- Positive (abnormal): A positive or abnormal test result means that parasites and/or eggs were found in your stool sample. You have intestinal parasites. Limitation: Treatment for an intestinal parasite infection will depend on the type of parasite you have and your general health. Next step: Treatment may include medicines that get rid of the parasites and/or relieve symptoms.
- A negative result does not completely rule out infection because parasites may not be present in every stool sample.
- The test relies on sample quality and proper collection; multiple samples over several days may be needed for accurate results.
What to do next
If you have questions about your results, talk with your provider. You will also need to drink plenty of fluids to prevent dehydration (the loss of too much fluid from your body) from the diarrhea and vomiting. You may be told not to swim until all your symptoms have been gone for at least two weeks.
- How many stool samples will I need to collect?
- What do my results mean for my health?
- Do I need any follow-up tests or treatment?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.