How fast do food poisoning symptoms show up?


How long after eating possibly contaminated food would one suffer the symptoms of food poisoning? And please advise if severe cramping, watery diarrhea, and vomiting are such symptoms.

— Ill

Dear Ill, 

Feeling queasy after eating that meal? Feel like you can't get to the restroom fast enough? Check, please! Food poisoning occurs after consuming foods or beverages that are inhabited by bacteria, viruses, or parasites. Typically, the timeframe for experiencing symptoms of food poisoning is anywhere from a few hours to a few days after consuming contaminated food. Although these symptoms may vary and may be mistaken as symptoms of other illnesses, the cramping, watery diarrhea, and vomiting may be the result of food poisoning. 

There are many different kinds of germs that can cause food poisoning, though most cases are caused by either Escherichia coli (E. coli) or staphylococcus. While their origins and transmission characteristics may vary, these organisms all enter the body through the gastrointestinal tract and may cause symptoms such as diarrhea, nausea, vomiting, and cramps. In addition to food poisoning, these symptoms can also be a sign of certain food allergies or other illnesses, so if you experience these symptoms every time you eat a particular food, you may want to work with a health care provider to determine whether you may be allergic to that food. 

While food poisoning symptoms usually go away in one to two days, some symptoms may last for up to ten days. It’s advised to seek immediate medical care if you experience: 

  • High fever (a temperature of 101.5° Fahrenheit or more) 
  • Bloody stools 
  • Frequent vomiting which prevents you from keeping liquids down 
  • Dehydration 
  • Diarrhea lasting more than three days  

List adapted from the Centers for Disease and Prevention Control (CDC)

To relieve the uncomfortable symptoms of food poisoning and prevent dehydration, some suggestions include: 

  • Giving your stomach a break by not consuming any food or drink for a few hours 
  • When you start eating again, eat bland foods and try to avoid dairy, caffeine, alcohol, nicotine, and spicy foods 
  • Sipping small amounts of liquids such as water, clear broth, or clear soda 
  • Resting up 

List adapted from Mayo Clinic

To protect yourself from foodborne illnesses, you may consider following these steps for food safety: 

  • Clean: Make sure to wash your hands before, during, and after handling food. It’s also wise to wash any surfaces or utensils before and after use. Additionally, rinse off fruits and vegetables before eating. 
  • Separate: Avoid cross-contamination by keeping raw eggs, meats, and poultry away from other foods and containers. 
  • Cook: It’s critical to cook all foods thoroughly and at the correct temperature. This minimum cook temperature chart can provide guidance as to which foods need to be cooked at which temperatures. 
  • Chill: Let the leftovers chill out by refrigerating any uneaten foods immediately. 

List adapted from FoodSafety.gov

If you believe you're sick due to food poisoning, reporting your symptoms and case to local governments can help them gather information about the potential causes, track illness, and prevent future outbreaks.

Here's to enjoying your food and not feeling sorry about it later! 

Last updated Apr 15, 2022
Originally published May 08, 1995