This may not be financially feasible, and it may not be as useful anyway. Have they checked him for a possible brain/spinal tumor?
I know Adam had a ball python die that had tumors everywhere..and showed no symptoms...
Regardless, I guess I would treat this as if it were IBD just to be safe.
Unfortunately it may be better to euthanize the snake in the long run, but I would keep trying to find out what happened first.
I know somebody else who had a boa that was exposed to a high dose of pesticide and started showing IBD like symptoms. The boa ended up having several neurological problems (from the pesticide) and had to be put down after about a year after the incident.
A reptile expo or reptile exposition is basically a reptile show.