What Is The Remedy For Diarrhea And Vomiting In A 14 Month Old Caused Due To A Fall?

Hi! My son is 14 months old (will be 15 mo. on the 21st). He fell down an entire flight of stairs 2 days ago. I took him to the ER immediately and they said that he was fine, had no head injuries whatsoever. The morning after he vomited once but hasn t done so anymore. And ever since he s been having diarrhea. Anything he eats or drinks basically shoots right through undigested. I ve tried pretty much anything. I ve been giving him clear fluids all along (Pedialyte, Pepperminttea, water), I ve tried feeding him bananas, potatoes mashed up with carrots, saltine crackers, dry bread. He either poops it out within the following 30 mins or refuses food and drinks completely. I can t really tel if he s passig enough urine either just because of the amount of BM. The BM s are very, very watery. Any more ideas? I d be very grateful for any type of help!!