What is a stool ova and parasites test?

Your doctor can order a stool ova and parasites (O&P) test to check for parasites and their eggs in your stool, or feces. It’s a relatively easy and common test. Your doctor will likely ask you to collect a sample of your stool at home. Then the sample will be delivered to a laboratory for testing.

If your stool tests positive for parasites or their eggs, your doctor will prescribe treatment to eliminate the infection.

Your doctor may order an O&P test for a few reasons. For example, they may order the test if you show signs and symptoms of an intestinal infection, such as:

  • frequent diarrhea
  • mucus or blood in your stool
  • nausea or vomiting
  • severe abdominal pain
  • headache
  • fever

In some cases, your doctor might order the test before you show signs of an infection. For example, if there’s a parasitic outbreak at your child’s day care or school, they may encourage your child to be tested. They may also recommend testing if you’ve recently traveled out of the country in an area where parasites are endemic or you’ve consumed untreated water.

There are many possible causes of intestinal symptoms, such as recent use of antibiotics. Along with the O&P test, your doctor will obtain a detailed history and may also order other laboratory tests. For example, they may also order a stool culture to check your stool for disease-causing bacteria.

In most cases, an O&P test doesn’t require special preparation. In some cases, your doctor may ask you to avoid using certain products before collecting a sample of your stool. For example, they may ask you to avoid taking:

  • laxatives
  • antidiarrheal medications
  • antibiotics
  • contrast dyes, which are used in imaging studies and X-rays

If your doctor orders an O&P test, you will need to provide a sample of your stool. Collect a small sample of your stool using latex gloves or plastic wrap. For example, consider covering the bowl of your toilet with a loose layer of plastic wrap before using it. The plastic wrap will catch your stool, making it easy to collect. Avoid mixing your stool sample with urine or toilet paper.

If you need to collect a sample of stool from your child, it may require additional steps. You may need to help them, especially if they’re not quite potty-trained. You can collect a sample of stool from their diapers, as long as the sample isn’t soiled with urine. In some cases, your doctor may recommend using a clean cotton swab to collect a sample of stool from their rectum.

After you’ve collected a sample of stool, place it in a clean container and seal it. Then take the sealed container to a clinic or laboratory, as instructed by your doctor. A technician will use dye and a microscope to look for parasites and eggs in your stool sample.

Your doctor will likely call when the results are available. They may be available in as little as two days or less.

A “normal” test result means that no eggs or parasites were found in your stool sample. If you receive a normal result but your symptoms haven’t subsided, your doctor may order additional tests or examinations.

An “abnormal” test result means that parasites, eggs, or both have been found in your stool sample. Parasitic infections in the United States are rare but can be caused by:

  • Cryptosporidium
  • Entamoeba histolytica
  • Giardia

Your O&P test may also detect:

  • Balantidium coli
  • Cyclospora cayetanensis
  • Dientamoeba fragilis
  • flatworms
  • hookworms
  • roundworms
  • tapeworms

Based on your test results, your doctor will recommend treatment or other follow-up steps. For example, they may prescribe antiparasitic medications. The goal of treatment is to relieve your symptoms and kill any parasites or other disease-causing organisms in your system.

Like other tests of its kind, the O&P test poses no health risks. Collecting a stool sample is an easy procedure that you can complete at home. If you experience difficulties producing or collecting a sample, call your doctor.

If you suspect you may have a parasitic infection, make an appointment with your doctor. It’s best to take the O&P test as quickly as possible. This can help your doctor treat your infection before parasitic eggs hatch in your lower intestinal tract.