What is the most common cause of infectious gastroenteritis?

• A. Viral gastroenteritis
• B. Bacterial gastroenteritis
• C. Parasitic gastroenteritis
• D. Fungal gastroenteritis

Answer: (A)

Viruses are the most common cause of infectious gastroenteritis. They spread easily through the fecal-oral route and contaminate food and water, leading to frequent, self-limited illness in people of all ages. Among viruses, norovirus is the leading culprit in outbreaks and widespread gastroenteritis, while rotavirus is a major cause in young children (though vaccination has reduced its impact). Bacterial causes such as Salmonella or Campylobacter do cause gastroenteritis too, but they account for a smaller share of total cases. Parasitic and fungal causes are relatively uncommon in the general population. So, the overall most common cause is viral gastroenteritis.