Stool Test: Ova and Parasites (O&P)

What Are Stool Tests?

Testing a stool sample can help doctors find out what's going on when someone has a problem in the stomach, intestines, rectum, or other part of the gastrointestinal (GI) system.

Unlike most other lab tests, parents might need to collect the stool (feces or poop) sample for the test (also called a stool culture or fecal test). The doctor or lab will give instructions on how to do this.

Depending on the type of test, results can be back in 24–48 hours or take 3–4 days.

What Is an Ova and Parasites Test?

An ova and parasites (O&P) test checks poop for parasites and their ova (eggs) or cysts, which are hard shells that protect some parasites at a certain stage in their lifecycle.

Why Are Ova and Parasites Tests Done?

Doctors may order an ova and parasites test if a child has symptoms of a parasitic infection, such as:

• diarrhea for several days
• blood or mucus in the poop
• belly pain
• nausea
• headaches
• fever

This test also is helpful if a child recently visited a developing country or goes to a school or daycare center that’s had an outbreak of parasitic illness.

If possible, your child may be asked to avoid some foods and treatments for 2 weeks before the test, including:

• antacids, antidiarrheal drugs, and laxatives
• antibiotics and antiparasite drugs
• enemas
• contrast materials (liquids taken before some X-rays, CAT or CT scans, or other imaging studies)

How Is the Test Done?

At the lab, a technician stains some of the stool sample with a special dye and looks at it under a microscope to identify any parasites or ova.

What if I Have Questions?

If you have questions about the ova and parasites test or what the test results mean, talk to your doctor.