Bacterial gastroenteritis is inflammation of the stomach and intestines caused by bacteria. Common symptoms include diarrhea, abdominal cramps, nausea and vomiting. Doctors diagnose it by examining patients for dehydration and testing stool samples. Treatment focuses on rehydration. Most cases resolve in a few days without antibiotics. It often occurs from eating contaminated food from improper handling or storage. Proper hygiene and food safety can help prevent bacterial gastroenteritis.