More than likely it is a bacterial infection from what I see. The swim bladder issue is in general a secondary thing. The other bummer is once they start the head standing, they usually don't come out of that one. How long have you had these fish and did you treat them at all when you got them? I will forward this to a good friend, Rodney, who owns Hawaiidiscus.com and maybe I can get him to chime in. IMO he is one of the best out there for discus and discus treatment.