As I have previously stated, Dr. Jacobson who is one of the foremost researchers on this disease has flat out stated that it lay dormant indefinitely and that it's far more common than we think.
Alex, you made reference to the Barker's. They are not vets, they are not researchers. They are snake breeders.
I can provide you a link to one of the foremost breeders of boas flat out stating in an interview that he believes IBD does not exist.
Any info coming from a breeder and not a researcher should be taken with a whole shaker of salt. Likewise any papers that are older than three or four years probably are outdated in terms of this disease.