Bacterial gastroenteritis can affect one person or a group of people who all ate the same food. It more commonly occurs after eating at picnics, school cafeterias, large social functions, or restaurants.
The germs may get into your food (called contamination) in different ways:
Meat or poultry may come into contact with bacteria from the intestines of an animal being processed
Water that is used during growing or shipping may contain animal or human waste
Improper food handling or preparation in grocery stores, restaurants, or homes
Food poisoning often occurs from eating or drinking:
Any food prepared by someone who did not wash their hands properly
Any food prepared using unclean cooking utensils, cutting boards, or other tools
Dairy products or food containing mayonnaise (such as coleslaw or potato salad) that have been out of the refrigerator too long
Frozen or refrigerated foods that are not stored at the proper temperature or are not reheated properly
Raw fish or oysters
Raw fruits or vegetables that have not been washed well
Raw vegetable or fruit juices and dairy products (look for the word "pasteurized" to make sure the food is safe to eat or drink)
Undercooked meats or eggs
Water from a well or stream, or city or town water that has not been treated
Many different types of bacteria can cause bacterial gastroenteritis, including:
If you have diarrhea and are unable to drink or keep down fluids because of nausea or vomiting, you may need fluids through a vein (IV). This is especially true for young children.
If you take diuretics ("water pills"), talk to your health care provider. You may need to stop taking the diuretic while you have diarrhea. Never stop or change medications without first talking to your health care provider.
Antibiotics are usually not prescribed for most common types of bacterial gastroenteritis, unless the diarrhea is very severe.
You can buy medicines at the drugstore that can help stop or slow diarrhea.
Do not use these medicines without talking to your health care provider if you have bloody diarrhea, a fever, or the diarrhea is severe.
Do not give these medicines to children.
You should be better in a few days without treatment.
Certain rare types of E. coli can cause severe anemia or even kidney failure.
Calling your health care provider
Call for an appointment with your health care provider if you have:
Blood or pus in your stools, or your stool is black
Diarrhea with a fever above 101°F (100.4°F in children)
Recently traveled to a foreign country and developed diarrhea
Stomach pain that does not go away after a bowel movement
Symptoms of dehydration (thirst, dizziness, light-headedness)
Also call your doctor if:
The diarrhea gets worse or does not get better in 2 days for an infant or child, or 5 days for adults
A child over 3 months old has been vomiting for more than 12 hours; in younger babies, call as soon as vomiting or diarrhea begins
Sodha SV, Griffin PM, Hughes JM. Foodborne Diseases. 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.
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., Inc.