No mites at all, and it definitely was IBD, they found out the cause of death from the necrops, it was Ecoli, they had it and salmonella that started acting up and the stress from the change of home is likely what caused them to die. Their immune system couldnt handle the Ecoli and salmonella acting up and they died from it combined with stress.
Did you mean to say it WAS (?) or WAS NOT (?) "IBD"?
It sounds like they were given a general diagnosis of septicemia due to an infection with the E.Coli. It is still strange to see it happen in several snakes at the same time, even if they did have poor husbandry.
6.10 Ball Pythons
1.1 Brazilian Rainbow Boas - "Marco and Esmeralda"
1.0 Jungle Jaguar Carpet Python - "Rossi"
1.1 Boa Imperator Rescues - "Clifford and Bonnie"
0.1 Hog Island Boa - "Luna"
1.0 Dumeril's Boa - "Sage"