When I get my BCI, I take it to the vet, he should be able to tell if carries IBD (even if it has no signs of it) correct?
Only if he does a necropsy of the BCI, which requires it to be dead first. Boas can be symptom-free carriers of IBD their entire lives, just like people can be carriers of tuberculosis and not know, except that IBD can't be tested for in a live patient yet.