If some of your constipation problems are due difficulty with relaxing the pelvic floor muscles, the best recommendation my PT made for me was a pelvic wand. It is silicone hook-shaped device that you insert through the rectum to "stretch" those muscles. It is very intimidating at first, but now I don't know what I would do without it. I bought mine through a company called Intimate Rose. Abdominal massage and a TENS unit have also been helpful for me.