Well, my ds (4) had diarrhea for 6 days and vomitting on day 1,2, and 6. It was really bad. He was actually sick the week previous to that with a fever for 5!! days and various other things like headache, tummy ache, vomitting, etc. He started getting a lot better and we had a beautiful weather day here so we went for a little walk. He splashed in puddles and even drank a bit of puddle water. Well, the next day is when the diarrhea started. It wasn't until a few days later that I thought about that puddle water.
When I mentionned it to my husband a possible source of the illness he replied "What, you let him drink from a puddle!".
(Obviously, I didn't 'let' him!)
Anyway - all that to say that I, too, wondered about the puddle water and all of the possible funk that might be in there....
I'll never know, though.
I do know that my son has never been as sick in his life as he has been during that time. Touch wood - he has recovered and is now back to bugging his big sister!
I hope that your little one continues to improve!
Also - we did take him to the doctor. The doctor (that never reacts to anything) read me the riot act with respect to dehydration. He essentially told me that dehydration can be fatal and to not take it lightly. Our goal was to keep him hydrated while his immune system took care of the infection. I went right to the store, threw all of my "healthy food ideals" away and bought all sorts of liquid options. I now know why hospitals have Jello!
Another liquid that worked well was my bone broth. You might also want to try freezing the peadilite into popsicles (or breastmilk popsicles, for that matter). If it goes down slower, it might stay down longer. And nurse, nurse nurse - even if it keeps coming up, some will be absorbed.
*Sending you healthy vibes*
I wish you both well!