Gastroenteritis, also known as stomach flu, is a medical condition that is characterized by inflammation of the gastrointestinal tract. The inflammation is mainly caused due to a pathogenic infection. The causal organism may be a virus, fungus, parasite or bacterium. Though the incidence of viral stomach flu is definitely higher than a bacterial infection in stomach and intestines, consumption of contaminated food may provide bacteria an opportunity to travel to the gastrointestinal tract. Once bacteria find a way into the gastrointestinal tract, they start multiplying. Inflammation of the gastrointestinal tract is the direct result of the spurt in the bacterial growth. Given below is some information on bacteria that cause inflammation of the digestive tract along with bacterial gastroenteritis symptoms and treatment options.