It does not look like bloat. ( i see no raised scales; only a big constipated belly ).
I have had a small Fh exactly like that. Was a monater feeder and simply ate too much.
After a couple of days like that ( i thought it would die ), more than a week, it got better.
What is the temps in the tank?
On another note, do you think you could pick it up and very very very gently, massage his belly ( the slightest pressure only ) and for 2 or 3 seconds only?
Ig you do mot feel at ease, don't do it. You don't want to squeeze anything out of there by force, okay?
And don't even try to feed it for the next couple of days.