The pedialyte is not a bad idea at all! When I was a kid, if I went from one side of town to the other, the difference in the water source would keep me in the bathroom for a day or two even after I got back to my "own" water. I come across this a lot with fish: just because your well water tested OK for human consumption doesn't mean that there isn't something in there that could be lethal to fish (like copper, for instance). However, if it's been a month, she should be coming to terms with it by now ... unless it's really messing with her (which it appears to be doing). Me? I'd try some of that "purified" water you can buy at the store. Not spring water, but stuff that's run through massive filtration systems. It couldn't hurt ... *I* drink bottled water! and when I travel, I have it for the dogs, too.
The pumpkin is also good for a case of the runs ...
Pollen usually gives them skin problems and sneezes/coughing; I've never associated pollen allergies with the "runs".
Other suggestions given above about being able to give her more room are good - she could be reinfecting herself because she can't get far enough away from her own waste.
Whatever the answer is, I hope you find it soon. EVERYone is miserable when the baby's sick
