Hi, M.. First I would have her seen by a doctor who can check to make sure there are no blockages or growths in her bowels and intestines, other than the long colon, you know to make sure the plumbing isn't clogged or blocked. They could be missing something and the only way they can find any of this is to do a colonoscopy.
There are also some very good herbal remedies and formulas on the market. I would contact an herbalist, check the internet and get some books on herbs and their uses. I am not sure but I am sure there is some kind of herbs that can help this situation. I also would look at all the vegetables and fruits, organic of course, to see which ones help promote bowel movements. I also would cut sugar from her diet and push more fluids.
I believe that some of the products we find on our store shelves are so over processed and so many additives that they are causing harmful side effects on our systems.
Hope some of this is useful. Good luck.