Is my fishy constipated??

[OfPirateMind]

I swear, it's always something. I've been observing this discus for a couple of days and I noticed he's looking a little fat, like he swallowed a marble or something. He's not behving ill, he's swimming/eating normally. Could he be constipated? Would aquarium salt work the same as epsom salt? Or should I use another treatment?
I tried to get a good shot of him from behind, but I can't post it, file is too large

[m.ingram]

He might just be fat from eating alot but it still doesnt hurt to put in epsom salt it just gives them a good clean out .

[OfPirateMind]

He might just be fat from eating alot but it still doesnt hurt to put in epsom salt it just gives them a good clean out .

Will aquarium salt work?

[m.ingram]

No aquarium salt wont work use epsom salt .