Goldfish Help!

[chigwellhammer]

My girlfriend is saying that her goldfish is staying at the bottom of the tank not swimming much and keeps falling to its side and his underneath is going a bit white. This is coming from my blonde girlfriend but im going over there tomorrow so ill check him out better then but if anyone has any ideas what is wrong then please do say.

Thanks
Jamie

 

[Twinklecaz]

Is the thank big enough (at least 100L for one Goldfish) and water stats good?

If so then I dunno, swimming problem could be Swimbladder? Or he could be overfed or constipated?