Hey There,
I wouldn't worry. BP's digestive system is very efficient and can break down pretty much anything. There are some cases of Aspen causing an animal to become impacted but my guys have swallowed plenty of aspen and have never had any issues. One thing I have noticed is when the prey size is too small than alot of Bedding is able to get pulled into the snakes mouth. I noticed virtually no Aspen being digested when I went to bigger prey animals.
Cheers.