Viral Gastroenteritis
    Astrovirus gastroenteritis, seen principally in young children, resembles a mild form of rotavirus gastroenteritis.  After an incubation period of 1-4 days, watery diarrhea lasts for another 1-4 days or more and is accompanied by abdominal discomfort, vomiting, and constitutional symptoms.  Immunity probably lasts for years, and most adults are resistant to experimental infection.  Less severe responses develop following subsequent exposure to one of the other serotypes.

Viral Diarrhea
    Astrovirus infection is also a major cause of viral diarrhea.  As in astrovirus gastroenteritis, astrovirus diarrhea lasts for 1-4 days or more following an incubation period of 1-4 days.