Intestinal parasites are parasites that lives in in humans and other animals, it's a matter if you have them or not! Parasites can get into the intestine by going through the mouth from uncooked or unwashed food, like restaurants MCdonalds. Due to the wide variety of intestinal parasites, many symptoms can be active such, Abdominal pain, chest pain, diarrhea, mental problems, Weakness...ect. To know if you have those parasites get a stool sample to the doctors.
Note: I've read that you can get those parasites by eating pork.