Forty percent of cases are idiopathic. Children attending day care centers may have rates 3 times higher. Gastroenteritis results in 220,000 hospital admissions and 300 deaths per year. Five to 10 million deaths per year are attributable to diarrheal disease in children. Norwalk virus is a more common virus in school-aged and adolescent children.
Outbreaks occur yearly in schools, camps, and other group settings.
Infants and small children are at higher risk for significant volume depletion. Assessment of volume depletion by history and physical examination guides the therapy of patients with uncomplicated gastroenteritis. Pertinent questions related to etiological factors help differentiate viral gastroenteritis from invasive bacterial disease, food poisoning, appendicitis, urinary infections, and other diseases. The physical examination should confirm and clarify the assessment of the severity of volume depletion and should narrow diagnostic possibilities generated by the history. It can occur year-round, but in temperate zones, it has seasonal peaks in cooler months.