Giardia Infections
Educational information. Individual clinical review of this presentation by Dr. Ehsan is not yet documented. It does not replace personal medical evaluation.
Source: MedlinePlus, National Library of Medicine. Read the original source
MedlinePlus data edition September 26, 2026. Imported September 27, 2026. These dates do not indicate a new clinical review of the article.
Giardiasis is an illness caused by a parasite called Giardia intestinalis. It lives in soil, food, and water. It may also be on surfaces that have been contaminated with waste. You can become infected if you swallow the parasite. You can also get it if you're exposed to human feces (poop) through sexual contact.
The risk of getting giardia is higher for travelers to countries where it is common, people in child care settings, and those who drink untreated water.
Diarrhea is the main symptom of giardia infection. Others include:
- Passing gas
- Greasy stools
- Stomach cramps
- Upset stomach or nausea
These symptoms may lead to weight loss and loss of body fluids. Some people have no symptoms at all. Symptoms of infection often last two to six weeks. Stool sample tests can diagnose it. You often need to collect several samples to test. Doctors use several drugs to treat it.
The best way to prevent giardia infection is to practice good hygiene, including frequent hand washing. You should not drink water that may be contaminated. You should also peel or wash fresh fruit and vegetables before eating.
Centers for Disease Control and Prevention
Symptoms, tests and care options
Further reading selected by MedlinePlus. Links open the original organizations’ websites.
- Diagnosis of Parasitic Diseases · Centers for Disease Control and Prevention
- Ova and Parasite Test · National Library of Medicine
- String test for intestinal parasites · Medical Encyclopedia
- Symptoms of Giardia Infection · Centers for Disease Control and Prevention
- Treatment of Giardia Infection · Centers for Disease Control and Prevention
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