I know how frustating it is. Spend loads of money on Colon cleanses/ parasite cleanses etc just to find out the problem is still there.
I started doing Inversion therapy and Basic Yoga therapy, and have healthy bowels every day. You can either buy a Inversion table/ Yoga sling or just invert from ottoman. Try twisting your torso while inverted. Do situps/ crunches. Doing it on a daily basis should knock down constipation for good.
You see, good health comes from inside-out and not by taking any supplements, herbal or otherwise. Lay off your supplements and heal the body from inside.