If your BP is acting like that it might have some underlying problem. Could be sick. There is really no way to know without a reptile vet. It's quite possible, and very probable, that it has internal parasites. 15 years ago, the majority of BPs being sold in the USA were imports.

Internal parasites can cause a snake to act like that and lose it's appetite. You need to get a stool sample checked. If it isn't eating then it won't be pooping either. In that case, a precautionary dose of panacure by an exotics vet would be a good idea.

Of course you first want to rule out RI. In which case a mouth culture needs to be tested.