Help!!! Brand new betta acting weird, sideways+bloated, hiding!!!

[MauiFishForever]

I bought a new betta from petco literally like 2 hours ago. I put him in my five gallon tank, he is alone. The tank has been running for a week in preparation for a fish.
So here's the problem. An hour ago he was fine, swimming around exploring the tank. I fed him some pellets but he only ate one...i took the other out and gave him a flake, which he did not eat. Now his stomach seems a little bigger than usual(it was not like this an hour ago) and he is sorta floating diagonally in the tank, hiding beind the filter. The temperature is about 78-80 right now!! dont know what is going on.

[bettaXD]

Hmm.... check out http://www.bettatalk.com/betta_diseases.htm it will help you... feed the fish a boiled pea (no shell),make sure it eats it and fast it. :) My betta has the same problem to ;(

[MauiFishForever]

yeah i've read that...maybe its just stress because of the change...i did just get him...he seems a little better...we'll see. he's soooo beautiful i hate to see him like this