My BCI Won't Eat

[BOA68]

Well my new BCI Sox turned down food a couple days ago. I brought her home last Monday and she proceeded to go to the bathroom 3 times in 5 days. I think this is because she was being way over fed by her previous owners and was a little clogged up due to low temps in her old tank. She soaked for several hours before two of the movements. She looks much better now because before she looked very overweight. By the looks of her i think she has emptied herself out. I tried to feed her on Friday and she refused. She seemed interested at first and smelled the rat for a few minutes, but wouldn't take it. She was being fed Guinea pigs by her previous owners, could it be that she wouldn't eat the rat just because it didn't smell like a guinea pig??? Or is it possible that it was too early and she still wasn't ajusted to the new surroundings. She isn't showing any signs of sickness and the temp. and humidity in the enclosure are perfect. She also ate 3 days before i brought her home, so i know she has eaten recently and this wasn't a problem before.