A stool ova and parasites (O&P) test is used to detect parasites and eggs in the intestines. This is a relatively easy and common examination. You produce the sample on your own at home and the stool is then analyzed in a lab.
The O&P test can be ordered for a few reasons. A doctor may order this exam for patients who exhibit symptoms of an intestinal infection, such as:
- excessive diarrhea
- stools with mucus or blood
- severe abdominal pain
- nausea or vomiting
In some cases, a doctor might order the exam as a preventive measure before you even start experiencing symptoms of an infection. The O&P test is standard for children if there is a parasitic outbreak at daycare or school. You may also consider taking a voluntary test if you have traveled out of the country, or if you have consumed untreated water. It is easier to take the test as early as possible. This way, your doctor can help treat the parasites before any of their eggs hatch in the lower intestinal tract.
An O&P test usually doesn’t require preparation. In some cases, your doctor may ask that you avoid the following prior to collecting the sample:
- anti-diarrheal medications
- contrast dyes (used in imaging studies and x-rays)
After a doctor has given the go-ahead for the O&P test, you should obtain a stool sample at your convenience. Collect a small sample with the help of latex gloves or plastic wrap, and then place it in a clean, sealed container. Be careful not to urinate on the container or the sample.
Obtaining a stool sample from children requires additional steps. You may need to assist young children, especially if he or she is not quite potty-trained. Samples may be collected from diapers so long as they are not soiled with urine.
Once the stool sample is collected at home, take the sealed container to your designated lab. Here, the technician will use a dye on the sample to detect any parasites and eggs present. You don’t have to be present for the processing of the sample. Simply drop it off and wait until your doctor calls with the results.
Patients normally get test results back within two days (Nemours Foundation). A normal O&P test result means that no eggs or parasites are present. If you receive a normal result but your symptoms haven’t subsided, your doctor may order other tests.
Abnormal results mean that parasites, eggs, or a combination of both were found in the stool sample. According to the American Association for Clinical Chemistry (AACC), the most common parasites in the United States include:
- Entamoeba histolytica
Worms and other parasites may be detected with the O&P test, including:
- Balantidium coli
- Cyclospora cayetanensis
- Dientamoeba fragilis
Your doctor will treat the infection based on the test results. The goal of treatment is to get rid of the infection and reduce symptoms. Also, treatment will help get rid of the parasites and ova.
Collecting stool samples is an easy procedure done in the comfort of your own home. Like other tests of its kind, the ova and parasites exam poses no health risks. Simply follow your healthcare provider’s instructions and return the sample to the lab. If you experience difficulties producing stool, call your doctor.
The O&P test is commonly ordered if your doctor suspects related infections. Still, there are many other common causes of prolonged diarrhea other than parasitic infection. Your doctor may order a stool-culture in conjunction with the O&P test in case other problems are present. Stool cultures detect bacterial infections throughout the gastrointestinal (GI) tract.