After minor abdominal surgery I found that the prescribed opiates made the pain go away to where I felt like I could do everything I normally did. So, instead of resting like I should have I would try to do things and be in serious pain when the opiates wore off. Cannabis, on the other hand, I could still feel the pain but I could put it in the back of my mind. This allowed me to be aware that I needed to rest and heal and not be completely focused on the pain. I stopped taking the opiates after the first day.