Hi, sorry for jumping in here. I haven't read all the replies, so if this is a repeat of what anyone has already suggested, I apologize.
I've had whites for a very long time, and have found they prefer to have warmer temps during the day, I keep mine at just under 80, but they can tolerate up to about 82 (Fahrenheit).
If your frog is staying toward the bottom of the tank at higher temps, it suggests to me the humidity is too low so he is trying to stay low where the moisture is.
As far as your runny poop, this is sounds like a protozoan problem (I've treated one very sick froglet for this), but you must get a fecal sample to confirm. YOu can force feed if necessary, there should be a few threads on here about that.
but in the mean time, you may want to contact dr. frye (search on here for his contact info, I've used him many times), he can send you metro and baytril, and I would suggest treating right away, even before fecal test is performed. I would ask the advice of dr. frye, but i assume he would suggest the same.
once your frog is feeling better, he will begin eating. metro will stimulate his appetite as will the higher temps.
as far as red leg goes, I have never personally dealt with it in my frogs, but it is usually linked to the cleanliness of the enclosure. do you change and clean the water bowl daily? use very hot water and a papertowel to wipe the bowl - *daily*
Definitely contact dr. frye, milan animal hospital in Michigan. you can google his contact info and/or search the forum. He will work with you via email and with photos. he can ship you medication, which sounds like you desperately need at this point.
good luck!