Em...I think that this was a really good question/thread.
I smoke weed here and there occasionally...if I do its mostly for pain relief or as a sleep aid. My boyfriend has Crohn's disease so he smokes weed for the pain associated with it and therefore its around me a lot of the time, and I have to say that despite not ever being someone who smoked it on any sort of regular basis, i'm gaining more of an appreciation for it's medicinal purposes.
I *fucked* my knee up royally not too long ago snowboarding, and went to the doctor who was going to put me on all sorts of colourful painkillers...which he explained were very easy to become dependent on, and with a long list of potential side effects...the knee injury wasn't even that severe either...so, I just wasn't comfortable pumping my body with that much medication. Instead I iced it and got my sweetie to give me bud cookies whenever I had pain. When you aren't ingesting the smoke, (and in my opinion, even when you are) marijuana is SUCH a better alternative to pain medications. I'm not saying post surgery you aren't going to be taking pain meds...you obvioulsy will be...but I would definitely try to encorporate the marijuana in there for sure.
I'm a fan of well made cookies (I can get a recipe for you, if you like) that have choice bud in them (I happen to live in B.C...sub-par bud just isn't even an issue here so that's why i'm saying that). They'll knock out the pain and help with any post op nausea etc etc etc.
Anyways, i'm obviously part of the yes vote...either way, hope the surgery goes smoothly for you!

good luck!
Bookmarks