I know this was a while ago, but saw it & thought i would add to it with my experience.
My youngest corn who is a fully grown adult, swallowed a tiny piece of aspen with his 1st feed with me. After some time I found he was passing blood in his stools. I visited the vet straight away, who did blood tests to check his liver & kidneys...the tests came back normal. As an extra precaution he carried out what is called a 'Flagyl' which I was told is a small soft tube that they pass through the snakes mouth & into the stomach & use a substance that 'flushed' anything like that out & also gets rid of internal parasites etc.
Ever since he had this done at the vet, he had one almighty pooh & has been fine . No more blood has been found. I am putting it down to this piece of aspen, maybe getting lodged or causing a tear somewhere ???
He is all good now...