Gastroenteritis is an inflammation of the stomach, small intestine, or large intestine presenting with abdominal pain, cramping, nausea, vomiting, fever, and diarrhea. It is one of the most common global illnesses, contributing substantially to morbidity and mortality, with the greatest burden in children and the elderly, where it may range from asymptomatic infection to severe dehydration and death. Acute gastroenteritis lasts <14 days, persistent 14–30 days, and chronic >30 days.