Gastroenteritis is a medical condition characterized by inflammation of the gastrointestinal tract, which includes the stomach and small and large intestines. It is commonly referred to as "stomach flu" or "stomach virus," although it is not caused by the influenza virus. Gastroenteritis can be caused by a variety of factors, including viruses, bacteria, parasites, and toxins. The symptoms of gastroenteritis typically include diarrhea, vomiting, abdominal pain, nausea, and fever. The condition can range in severity from mild to severe, and it is usually self-limiting, meaning that it resolves on its own within a few days without the need for medical treatment. However, in some cases, particularly in young children, the elderly, and people with weakened immune systems, gastroenteritis can lead to serious complications such as dehydration, electrolyte imbalances, and malnutrition.