Most snakes being medicated, especially by injection, will be too stressed to eat, or may lose their appetite (feel poorly) due to the medication (ask your vet for his specific Rx). As you said, he also might regurgitate- so for these reasons, most people don't feed during treatment. But, if he seems hungry & you think he'll eat (AND your vet says it's okay), I'd only offer a much smaller than normal-size meal- more of a snack that is easily digested. His RI is likely to make him refuse food, & 2 months isn't that long of a time for a BP, unless he's young-?