I had a stomach flu the other day. Wanted it so much to have some 水米 to help recover. Couldn't help throwing up.
My doctor said don't even bother to try 水米. What was needed is only fluid. The best one actually is soft drinks. Coke, Diet Coke, juice, Dr. Pepper, ginger rale, etc. because they are fluids and have some suger in them. So it is not that hurting the weak stomach. And she said no need to drink them a lot at one time, just sip, sip and sip whenever it is OK.
It worked to help me recover. Gee, I don't drink soft drinks at all because I think they are junks. And every time I was sick, I sticked to our Chinese rice porridage to feel better... but now I know junk drinks are good when I am sick.
I think you can get some drinks from Walmart phamacy just for younger kids. They are the same, some fluids with suger. Good luck.