I would discard anything they came into contact with and disinfect everything with an antiviral/antibacterial etc.

If it is IBD, it's extremely pervasive and I'm unsure how you'd actually get rid of it completely to be able to bring in more snakes. There's someone I know of on another site that had an IBD outbreak wipe out her collection, but I don't recall if she ever brought in more snakes or not.

GOod luck. I definitely would NEVER even go into the place you got them again, but I would call to tell them that both snakes died of suspected IBD in case they don't know.

It's a real pity you can't have them tested, as that could tell you definitely if it was IBD. The last time I priced necropsy, it was about $70 plus the shipping if you need to ship the body to whereever you choose. Not cheap.