I've had terrible constipation problems for years too, and the same kinds of experiences with cleansing, butt pee, stopped up, etc...
I've noticed that eating a couple of helpings of Organically grwon Short Grain Brown rice will keep me moving regularly better than anything else.
It has to be short grain. The long grain brown rice doesn't work for me. Apparently the short grain has more fiber. You can get it in packages by Lundgren.