Some people with giardia infection never develop signs or symptoms but still carry the parasite and can spread it to others through their stool. For those who do get sick, signs and symptoms usually appear one to two weeks after exposure and may include:
- Watery, sometimes foul-smelling diarrhea that may alternate with soft, greasy stools
- Fatigue or malaise
- Abdominal cramps and bloating
- Belching gas with a bad taste
- Weight loss
Signs and symptoms of giardia infection usually last two to four weeks, but in some people they last longer or recur.
When to see a doctor
Call your doctor if you have loose stools, abdominal bloating and nausea lasting more than a week, or if you become dehydrated. Be sure to tell your doctor if you're at risk of giardia infection — that is, you have a child in child care, you've recently traveled to an area in which you know giardia infection is present, or you've swallowed water from a lake or stream.
Nov. 14, 2012
Wright SG. Protozoan infections of the gastrointestinal tract. Infectious Disease Clinics of North America. 2012;26:323.
- Giardia. Centers for Disease Control and Prevention. http://www.cdc.gov/parasites/giardia/. Accessed July 18, 2012.
- Longo DL, et al. Harrison's Online. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=4. Accessed July 18, 2012.
- Leder K, et al. Epidemiology, clinical manifestations, and diagnosis of giardiasis. http://www.uptodate.com/index. Accessed July 18, 2012.
- McPhee SJ, et al. Current Medical Diagnosis & Treatment 2012. 51st ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=1. Accessed July 18, 2012.
- Munoz FM. Treatment and prevention of giardiasis. http://www.uptodate.com/index. Accessed July 18, 2012.
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