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 Canada and 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 (recurring).
Infection with the parasite can be prevented by handwashing 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 illness.
Current as of: November 14, 2014
Author: Healthwise Staff
Medical Review: E. Gregory Thompson, MD - Internal Medicine & Anne C. Poinier, MD - Internal Medicine & W. David Colby IV, MSc, MD, FRCPC - Infectious Disease
Public Health Alerts
Public health alerts include information about outbreaks, advisories and product recalls. Click on the links below to read the most recent alerts, or visit our Public Health Alerts web page.
FIND Services and Resources
If you are looking for health services in your community, you can use our directory to FIND hospitals, clinics, and other resources.
To learn more, visit Healthwise.org
© 1995-2015 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Is it an emergency?
If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be life-threatening. Call 9-1-1 or the local emergency number immediately. If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.