Bacterial gastroenteritis is inflammation of the stomach and intestines caused by bacteria.

Bacterial gastroenteritis 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:

• Meat or poultry may come into contact with the normal bacteria from the intestines of an animal being processed.
• Water that is used during growing or shipping may contain manure or human waste.
• Food handling or preparation in grocery stores, restaurants, or homes.

Food poisoning often occurs from eating or drinking:

• Any food prepared by someone who does not use proper hand washing techniques
• Any food prepared using cooking utensils, cutting boards, or other tools that are not fully cleaned
• Dairy products or food containing mayonnaise (such as coleslaw or potato salad) that have sat 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 (look for the word "pasteurized")
• 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:

• Campylobacter jejuni (see: Campylobacter enteritis)
• Clostridium
• E. coli (see: E. coli enteritis)
• Salmonella (see: Salmonella enteritis)
• Shigella (see: Shigella enteritis)
• Staphylococcus
• Yersinia