Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Viral Gastroenteritis ?
    ### Response:
    Four types of viruses cause most cases of viral gastroenteritis.
                
Rotavirus
                
Rotavirus is the leading cause of gastroenteritis among infants and young children. Rotavirus infections are most common in infants 3 to 15 months old.
    