What most naturally follows?

How to care for a child with diarrhea
Check for symptoms of viral infection.
There are many causes for diarrhea in children, but the main cause is often a viral infection, such as rotavirus. Viral infections are often accompanied by many other symptoms including headache, stomachache, vomiting, and fever.
Diarrhea, especially caused by viral infection, often lasts between five and fourteen days. Check your child's temperature with a medical thermometer to see if they have a raised body temperature, which is often another sign of viral infection.