Giardia infection (Giardiasis)


The diagnosis of giardia infection usually involves analyzing the stool for the presence of the Giardia parasite. For precision, multiple stool samples gathered over several days. These samples are then analyzed in a laboratory to detect the presence of parasites. Stool tests may also be employed to assess the effectiveness of any treatment one has undergone.

In cases of severe symptoms, an upper endoscopy may be performed. This involve using a thin, flexible tube to examine the intestines. The healthcare provider may collect a sample from the intestinal tissue (biopsies) to specifically search for parasites.


Generally, treatment is typically not necessary for children or adults with giardia infections who do not exhibit symptoms unless they pose a risk of spreading the parasites. Even those who do experience issues frequently recover on their own in a matter of weeks.

Treatment for giardia infection is recommended in cases of severe symptoms or persistent infection.

Medications include:

  • Metronidazole is the most commonly used antibiotic for giardia infection. Avoiding alcohol consumption is also recommended when taking metronidazole.
  • Tinidazole is as effective as Metronidazole and can be administered in a single dose.
  • Nitazoxanide, available in liquid form, may be more suitable for children because it is easier to swallow.

These medications have potential side effects that one needs to discuss with the healthcare provider. It is important to take each prescribed pill as directed. Failing to do so may result in not completely clearing the infection, requiring a second round of medication to fully eliminate the parasite.

Pregnant individuals may not have consistently recommended medications for giardia infection due to potential harm to the fetus. If treatment is necessary, alternative options may be suggested. If symptoms are mild, treatment may be postponed until after the first trimester or later.