Diagnosis

Food poisoning is often diagnosed based on a detailed history, including how long you've been sick, your symptoms and specific foods you've eaten. Your doctor will also perform a physical exam, looking for signs of dehydration.

Depending on your symptoms and health history, your doctor may conduct diagnostic tests, such as a blood test, stool culture or examination for parasites, to identify the cause and confirm the diagnosis.

For a stool culture, your doctor will send a sample of your stool to a laboratory, where a technician will try to identify the infectious organism. If an organism is found, your doctor likely will notify your local health department to determine if the food poisoning is linked to an outbreak.

In some cases, the cause of food poisoning can't be identified.

July 15, 2017
References
  1. Foodborne germs and illnesses. Centers for Disease Control and Prevention. https://www.cdc.gov/foodsafety/foodborne-germs.html. Accessed Jan. 31, 2017.
  2. Centers for Disease Control and Prevention, et al. Diagnosis and management of foodborne illnesses: A primer for physicians and other health care professionals. MMWR. 2004;53:1. https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5304a1.htm. Accessed Jan. 31, 2017.
  3. Acheson DWK. Patient information: Food-poisoning (foodborne illness). http://www.uptodate.com/home. Accessed Jan. 31, 2017.
  4. Foodborne illness. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/digestive-diseases/foodborne-illnesses. Accessed Jan. 31, 2017.
  5. The big thaw — Safe defrosting methods for consumers. Food Safety and Inspection Service. https://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/safe-food-handling/the-big-thaw-safe-defrosting-methods-for-consumers/CT_Index. Accessed Jan. 31, 2017.
  6. Wanke CA. Approach to the adult with acute diarrhea in resource-rich settings. http://www.uptodate.com/home. Accessed Jan. 31, 2017.
  7. Gelfand MS. Treatment, prognosis, and prevention of Listeria monocytogenes infection. http://www.uptodate.com/home. Accessed Feb. 3, 2017.
  8. Gelfand MS. Clinical manifestations of Listeria monocytogenes infection. http://www.uptodate.com/home. Accessed Feb. 3, 2017.