We were Air Force (many years ago) when my two boys had the diarrhea for what seemed to be months (but no vomitting). One nice woman in the commissary told me about Pedialite which was a blessing. All the DW's toted the BRAT diet (Bananas, Rice, Applesauce Toast) which didn't help me but what DID help was YOGURT! One pediatrician in Hawaii said it was probably a bacteria imbalance and the active cultures in yogurt should correct it. By golly that worked for them! I would try that along with all the other help but certainly won't hurt them.
D. (mother of five grown kids and now grandmother of five)