If a teen was doing study abroad and ate a lot of street food, how do I get him to go for parasite tests?

Stool examination. S/he does not need to go to a doctor. Your doctor can order a stool examination and s/he has to provide a stool sample. It would be useful to tell the doctor and the lab doing the test about the countries the student was in. Please note that if the student does not have any symptoms, there is no need for a parasite examination.