Why does Dr. Clark request stool samples for examination? Select all that apply. View Available Hint(s) Select all that apply. He will have the laboratory prepare the samples for an ova and parasite (O&P) exam. Fresh or preserved stool samples can be observed microscopically for the presence of parasites or their eggs/cysts. Dr. Clark is hoping to find whole adult parasitic worms in Michael’s fecal matter. Tapeworms are pathogens of the gastrointestinal tract; as a natural progression of digestion some of the tapeworm pieces will be expelled along with fecal matter. The stool sample will tell Dr. Clark more information about the vegetables in Michael’s diet.