Testing and Diagnosis for Giardia Infection

Key Points

  • Talk to a healthcare provider if you think you may be sick from Giardia.
  • They may ask you for stool (poop) samples to check for Giardia.
  • If you have Giardia in your poop, it means Giardia is likely making you sick.
Parent and child looking at a tablet with a healthcare provider

Why get tested

Many kinds of germs can cause diarrhea. Knowing which germ is making you sick helps your healthcare provider decide what treatment to give you.

Who should be tested

If you have diarrhea or other symptoms of a Giardia infection, talk to a healthcare provider about whether you should get tested.

Testing methods

To see if Giardia is making you sick, a healthcare provider will ask you for one or more stool (poop) samples. They will send your samples to a laboratory to check if you have Giardia germs in your poop. If the laboratory finds Giardia in your poop, it means you have a Giardia infection.

You may be asked to submit several stool samples collected over several days to see if you have a Giardia infection. The laboratory may need several samples because it can be difficult to detect Giardia in poop. Even if you have a Giardia infection, there may not be enough Giardia germs in every stool sample for the laboratory to find them. Additionally, people with Giardia infections do not pass Giardia germs every time they poop.