L.U.
T. - I am surprised that the "dr" just felt her back and was able to "feel" yeast and "feel" that good bacteria was missing. He must be a magician.
THat seems like a crock.
One of my sons gets sick a lot, and one of them rarely gets sick. While I am not a fan of antibotics, sometimes they are a necessity. 3 years old and runny diarhea does not sound like fun, and it's HURTING her. I would stop if I were you.
Put her on the BRAT diet (Bananas, Rice, Applesauce, Toast) and try and get her belly to calm down.
If she is in daycare, church daycare, around kids at play areas, moms groups..ect., she is going to be exposed to all kinds of germs. She'll get sick. She is only 3, so it's still kind of early (I think) to say that things are usual or unusual.
Good Luck to you, and I hope your daughter's belly starts to feel better.
L.