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Giardia Lamblia Symptoms
Common signs and symptoms of Giardia lamblia include diarrhea, bloating, vomiting, and abdominal pain. The symptoms usually occur within one to two weeks after becoming infected. In otherwise healthy people, Giardia lamblia symptoms may last two to six weeks. People who have chronic giardiasis may have slightly different symptoms, such as increased gas, dehydration, burping, and loose stools.
When a person becomes infected with the parasite that causes giardiasis (Giardia lamblia), the parasite begins to multiply within the intestines. Within one to two weeks (the average is seven days), the infected individual will begin to develop Giardia lamblia symptoms. This period between initial infection and the start of symptoms is called the "Giardia incubation period."
Symptoms of Giardia lamblia may begin gradually or develop without warning. Some people who have giardiasis may not have any symptoms at all, while others may experience severe symptoms.
Symptoms often vary from patient to patient, but the most common intestinal symptoms include:
- Diarrhea
- Upset stomach or nausea
- Vomiting
- Greasy stools that tend to float
- Stomach cramps
- Gas or flatulence
- Abdominal pain
- Bloating
- Belching.
These symptoms may lead to weight loss and dehydration.
Chronic giardiasis is a more severe form of the condition and can last for months or even years. The symptoms seen in patients with chronic giardiasis can be different from those who develop an acute Giardia infection. Common symptoms of chronic giardiasis include:
- Increased gas (flatus)
- Dehydration
- Burping
- Loose stools
- Slowed growth.
These chronic symptoms may come and go or always be present.
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD



