Yes. A doctor can test stool for Candida. They start by taking a stool sample and then examine it under a microscope to look for Candida overgrowth. They will then incubate a small sample for a few days to observe yeast that can grow in the stool. However, one of the most common ways to test for Candida is by testing for invasive candidiasis by procuring a blood sample from the infected body site and sending it to the lab. Once at the lab, researchers will see if Candida grows in the culture.