IBD isn't usually that fast in Boas
From healthy-seeming to corkscrewing to almost dead in a few days sounds like an environmental toxin, or less-likely a cooked snake from a too hot environment (sunlight?). Even BPs, who die quickly from the disease, don't usually go quite that fast from IBD.
Have insecticides been used anywhere near where the snake is in the at all recent past?
If this is your first snake, it would be good to hold off a couple of months before buying a new snake from a different breeder. IBD can stick around a little bit and wipes out whole collections. I don't add snakes to my collection, because I don't want to risk IBD even with a quarantine in a different part of the house. It's that dangerous, and my snakes are very important to me.
