What is the primary cause of noninvasive infectious diarrhea?

Noninvasive infectious diarrhea is primarily caused by viral infections, particularly in children. Viral pathogens, such as rotavirus and norovirus, are common culprits that lead to gastroenteritis, which is characterized by watery diarrhea, vomiting, and abdominal discomfort. These viruses tend to spread rapidly, especially in settings such as daycare centers and schools, where close contact facilitates transmission.

In contrast, bacterial causes of diarrhea, such as Shigella, Campylobacter, and Salmonella, are typically associated with more severe disease presentations. These bacteria tend to cause invasive infections, leading to symptoms such as dysentery, which includes bloody diarrhea and abdominal cramping due to tissue invasion. While bacterial infections can certainly cause diarrhea, the noninvasive type, commonly associated with a more straightforward viral pathogenesis, is primarily driven by viral agents, making the correct answer focused on viral infections.