Step-by-step explanation:
Ova and parasite (O&P) exam is microscopic evaluation of the stool sample which is used to look for the parasites which may infect lower digestive tract.
It is the test of any parasite which is infecting the digestive tract by the test of the stool sample because the parasites and the eggs are shed from lower digestive tract into stool.
The symptoms for the infection is frequent diarrhea, nausea or vomiting, headache, mucus or blood and fever.