I had a physical once, and my dr asked me if I "did any drugs". Being that I knew he got his degree from a university in the Netherlands, I thought he'd be understanding of cannabis use. I asked him if my response could be just between he and I (not entered into my medical record, as I didn't want it to affect life insurance, if I ever wanted to get some) and that I'd listen to any medical advice he'd give me about it. He responded "whatever you tell me, I will write here". So I said "then, no".

Most general physicians at hospitals will look negatively on cannabis use, especially if it's smoked. Smoking anything is bad for you. So I just tell them what they need to know unless it so happens that I can have an off the record discussion abou it with them. Otherwise, expect the type of response you got. Every doctor I've seen regarding mmj emphasizes that it's best to vaporize, followed by water pipe as a means of ingestion.