Giardiasis (also called giardia) is an illness caused by infection
with the parasite Giardia lamblia, also known as
Giardia intestinalis. Giardiasis is usually caused by
drinking water that is contaminated with the parasite. In the United States,
G. lamblia is most often found in untreated streams,
rivers, and lakes.
Symptoms of giardiasis include diarrhea, a lot of gas (flatulence),
abdominal cramps, and nausea. In some people, giardiasis does not cause any
symptoms. In other people, the symptoms may keep coming back
Infection with the parasite can be prevented by hand-washing and by
treating water taken from rivers, lakes, or streams before drinking it or using
it to cook, wash dishes, or brush teeth.
Symptoms of giardiasis may go away on their own. But medicine,
usually metronidazole, can relieve the discomfort and prevent the spread of the