Food poisoning


Food poisoning occurs when you swallow food or water that contains bacteria, parasites, viruses, or toxins made by these germs. Most cases of food poisoning are from common bacteria such as Staphylococcus or E. coli.


Food poisoning can affect one person or a group of people who all ate the same contaminated food. It more commonly occurs after eating at picnics, school cafeterias, large social functions, or restaurants.

The germs may get into the food you eat (called contamination) in different ways:

Food poisoning often occurs from eating or drinking:

Many types of germs may cause food poisoning, including:

Infants and elderly people are at the greatest risk for food poisoning. You are also at higher risk if:

Pregnant and breastfeeding women have to be especially careful to avoid food poisoning.


Symptoms from the most common types of food poisoning usually start within 2 - 6 hours of eating the food. That time may be longer or shorter, depending on the cause of the food poisoning.

Possible symptoms include:

Exams and Tests

Your health care provider will examine you for signs of food poisoning, such as pain in the stomach and signs your body does not have as much water and fluids as it should. This is called dehydration.

Tests may be done on your stools or the food you have eaten to find out what type of germ is causing your symptoms. However, tests may not always find the cause of the diarrhea.

In more serious cases, your health care provider may order a sigmoidoscopy. A thin, hollow tube with a light on the end is placed in the anus to look for the source of bleeding or infection.


You will usually get better in a couple of days. The goal is to make you feel better and make sure your body has the proper amount of fluids.

Getting enough fluids and learning what to eat will help keep you or your child comfortable. You may need to:

If you have diarrhea and are unable to drink or keep down fluids, you may need fluids given through a vein (by IV). This is especially true for young children.

If you take diuretics, ask your health care provider if you need to stop taking the diuretic while you have diarrhea. Never stop or change medications without first talking to your health care provider.

For the most common causes of food poisoning, your doctor will NOT prescribe antibiotics.

You can buy medicines at the drugstore that help slow diarrhea.

Outlook (Prognosis)

Most people fully recover from the most common types of food poisoning within 12 - 48 hours. Serious complications can occur, however, from certain types of food poisoning.

Death from food poisoning in people who are otherwise healthy is rare in the United States.

Possible Complications

Dehydration is the most common complication. This can occur from any causes of food poisoning.

Less common, but much more serious complications depend on the bacteria that are causing the food poisoning. These may include:

When to Contact a Medical Professional

Call for an appointment with your health care provider if you have:


See: Preventing food poisoning


Schiller LR, Sellin JH. Diarrhea. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 15.

Sodha SV, Griffin PM, Hughes JM. Foodborne disease. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 99.

Craig SA, Zich DK. Gastroenteritis. In: Marx JA, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier;2009:chap 92.

Review Date: 1/10/2011
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
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