This document discusses viral gastroenteritis, also known as viral diarrhea. It is caused by several viruses that infect the epithelial cells of the small intestine including rotaviruses, noroviruses, astroviruses, adenoviruses, and sapoviruses. Rotaviruses are the leading cause of infantile diarrhea. The viruses cause destruction of intestinal cells leading to malabsorption of fluids and electrolytes and symptoms like watery diarrhea, vomiting, and abdominal pain. While usually self-limiting, viral diarrhea can cause dehydration in infants and young children. Prevention focuses on handwashing and disinfection, and rotavirus vaccine provides protection against the most common cause.