Illness may be mild to severe. Stool can pollute streams, lakes, and ground water. This contaminated water is a common source of infection. Some people have no symptoms. The parasite is found in the stool of an infected person or animal.
Giardiasis is treated with medicine.
Some cases may require more than one course of treatment. Drink plenty of liquids to replace those lost through diarrhea. If not treated, people may have diarrhea for weeks or months. Wash your hands especially after using the toilet, before touching food, and after changing a diaper. Keep children home from day care or school if they are having diarrhea.