First, let me start by saying that I do not have access to "real" medical grade marijuana, nor have I been fortunate enough to try it. My experience below is with street grade marijuana that I find more useful than many of the prescription drugs I have tried.
Many years ago, I was diagnosed with what my doctors believe to be Ankylosing Spondylitis. Pain is almost constant in my hips and every few days I will have very uncomfortable lower back pain. The extent of my pain relief depends on the quality of the herb that I use. Mids will make the pain much more dull, and allows me to ignore it moreso than I would without marijuana. Real dank stuff will make my pain much softer, and the marijuana allows me to walk almost entirely without assistance or a limp.
I guess the best way to describe it on a smaller scale would be to take your fingernail, and firmly scratch your arm. Kinda burns, stings maybe. This would be my pain without marijuana. Now, with the same amount of pressure, rub your arm with your thumb. You feel the pressure on your muscle, but there isnt any stinging or pain really associated with it... this is approximately how my hip and spine pain is effected. I hope this helps a little, but Im sure that everyone who uses marijuana for pain relief has a different experience.
And one more thing, lying in bed can cause me a lot of pain as well, which then causes me to toss and turn a lot at night (which causes even MORE pain). I usually miss out on a lot of sleep because of this. With marijuana, I can stay still much easier and become much more comfortable with very little movement. After I get comfortable, I just let the herb take me to sleep and wake up feeling fantastic

Good luck to your father, hopefully he will give marijuana a chance
