Apparently he's been suspended 4 games for violating the league performance enhancement rules. No word on what the substance was though.
He's a good kid and I hope this wasn't something too strange. This happens to a lot of rookies who run into the league's extremely stringent testing program for the first time. When they say random testing, they really mean random. I remember a few years ago watching Chris Cooley tell of a time where a former player he was with got tested at his wedding. Some guy comes in with a little cup and a suitcase, escorts you to the restroom and stands there right beside you and watches. Perhaps the most thankless job in history.
Anyway, I hope this doesn't dampen the spirits for young Bolden and he learns from it.