IBD kills BP within weeks so it is very unlikely that if your BP has indeed IBD she contracted it prior to being in your possessions!

Pandora (my newly acquired Dumeril's Boa).
How long have you had your Boa for? (Boas can be asymptomatic carrier)

As your male BP shown any symptoms?

Could your female BP been in contact with any type of chemicals?

Could the enclosure have overheat for a prolong amount of time?