BP ate a piece of substrate

[Cake]

My BP missed the mouse when feeding and got a mouthful of substrate(bark). I went and grabed a set of tweezers to pull the bark out of its mouth but but the time i got back he had just finished swallowing a small peice. I know he will be unable to digest the bark, and im wondering if it could cause any serious effects. He did feed emidiatly after injesting the bark. It has been about a week now and he has not produced any excrement. This suggests that his intestine may be blocked, or paritially blocked.

Does anyone have any suggestions or any experience with a similar situation?

Thanks