Yeah, but "to run by/past" is more of a colloquialism anyway (which are actually the most difficult thing in every language since they follow as few rules as possible). "To discuss with" or something similar would be as accurate, and "with" would probably almost always be the correct preposition with them, as it would mean both parties were involved. "To speak to" would also be correct (in addition to "to speak with", but the prepostion "to" usually implies one-way action; I think "to speak to" meaning a discussion is also something of a colloquialism.

Sorry. I don't know why I'm going on and on about this.