I was just searching around on this, & some sources are now saying that a snake (such as a boa) CAN carry it for a couple years before becoming sick.
This is news to me so I'm sharing, not an expert on IBD...happily have never had a snake with it, or with anything remotely like it. I can see why Saml8 asked.
Excerpt from https://www.petmd.com/reptile/condit...n_body_disease
The symptoms of IBD may appear suddenly, but can also remain invisible and dormant for years, particularly in boas. Signs of IBD include:
Excerpt from https://www.wildlifehealthaustralia....13%20(1.3).pdf
"Quarantine periods as long as 13 months have been suggested but cases have occurred in snakes that were isolated fortwo years (P Holz, pers. obs.)."