Intestinal parasites refer to organisms that live in or feed off a host's intestines. These can include protozoa, helminths (worms), and ectoparasites such as tapeworms. They are often transmitted through contaminated food or water, or by contact with an infected animal. Intestinal parasites can cause a range of symptoms including abdominal pain, diarrhea, bloating, weight loss and malnutrition. Some species can also lead to more severe health problems such as anemia, liver damage or neurological disorders.