Well, I had similar symptoms most of my life, however I found eating All Bran for breakfast did keep me regular. After going primal, I found the old constipation came back pretty quick.
I sought advice from a natropath who prescribed this
It took a week or so but worked great and now I no longer require it.
This is an Australian product, so may be labelled differently overseas. Also, I could only get this through the practioner, so it wasnt cheap, but after two months I no longer required it so worth every $