Although I agree that senna plus usually works just fine if you give enough, I have heard that most laxatives actually can cause permanent motility problems if taken chronically (not sure I've ever seen that in a pt but I've read and heard about it many times). People who use large amounts of laxatives for long periods of time, like those with eating disorders who abuse laxatives, can actually end up dependant on them just for normal bowel function and often have lifetime issues with constipation even with laxative use (again this is something I haven't seen much but have heard lots).
I would assume those who use laxatives with opioids long term would have the same problem (I think there are a few,like maybe miralax, that don't do this but they are not always effective, I was always told that anything that increases motility can cause dependence). I wonder if these new meds don't have this problem? I could see if the cost comes down a bit but remains more expensive than senna and bisacodyl, that one could still justify it if it meant avoiding lifelong motility issues?