I know a couple people who work at our local pharmacy. They tell me that is how they know who the heavy users are because they are always buying heavy duty Exlax.
I had to create a "rule" for when I took it. One pain pill, two stool softeners, and wash them down with prune juice. The fact that I dislike the taste of prune juice helped me to get off the stuff after all those weeks in that lousy wheel chair.