A stool (feces) sample can provide valuable information about
problems in the stomach, intestines, rectum, or other parts of
the gastrointestinal (GI) system. In an ova and parasites (O&P)
exam, a technician views a sample of stool under a microscope to
look for parasites and their ova (eggs) or cysts, which are hard
shells that protect some parasites at a certain stage in their
lifecycle. Why It's Done A doctor may request an O&P exam if
your child has symptoms of a possible parasitic infection, such
as diarrhea for an extended period of time, blood or mucus in
the stool, abdominal pain, nausea, headaches, or fever,
especially if there's been an outbreak of parasitic illness at
your child's school or daycare center, your child recently drank
untreated water, or if your family recently visited a developing
country. Unlike most other lab tests, a stool sample is often
collected by parents at home, not by health care professionals
at a hospital or clinic. If possible, your child may be asked to
avoid certain fo