If you are experiencing severe, persistent, or bloody diarrhea, this is the definitive test to find the exact bacterial cause. A routine stool exam just looks for parasites, but this culture is a high-level investigation. It uses special, selective media to grow and identify pathogenic bacteria like Salmonella, Shigella, and Campylobacter. You will collect a small stool sample in a sterile container we provide. This test is the essential step to move from "stomach flu" to a specific diagnosis, guiding your doctor to the correct antibiotic (if needed) and getting you on the fastest path to recovery.