Gastroenteritis (also known as gastric flu, stomach flu, and stomach virus, although unrelated to influenza) is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water. The inflammation is caused most often by an infection from certain viruses or less often by bacteria, their toxins, parasites, or an adverse reaction to something in the diet or medication. At least 50% of cases of gastroenteritis resulting from foodborne illness are caused by norovirus...