Intestinal parasites are organisms that live in the digestive tract of humans and animals, feeding on nutrients from their host. Common types include protozoa, helminths (worms), and ectoparasites like lice. These parasites can cause various health issues, including diarrhea, abdominal pain, and malnutrition. Transmission often occurs through contaminated food or water, poor hygiene, or close contact with infected individuals. Prevention includes practicing good hygiene, cooking food thoroughly, and drinking clean water. Treatment typically involves medications that target the specific type of parasite present in the body.