My son has vomiting and diarrhea but no other symptoms. What should I do for him?

Vomiting and diarrhe. You did not say how old is ur son.You have to make sure he does not get dehydrated.Most of the time d&v is caused by virus, and will get better by itself, so only risk is dehydration due to loss of fluids. Give him clear liquids and pedialyte, if can not keep any fluid down try zofran (ondansetron) orally disintegrating tablets or phenergen suppository if he is more then 2 yrs old.If infant will need IV fluids.