Wow you sound just like me !!
I had back surgery in 2000, disk removed and ended up with perm numbness in my backside and down the back of the right leg .. have not been able to have regular bowel movements since. I do have bowel movements now but they are hard and small. I drink 2 liters of water each day which doesn't help and I also eat a lot of fruit and veggies which doesn't do much either
I just started putting flaxseed into my diet so I hope that does helps. I wish I could tell you how to fix it but I can't really, I take laxitives about every 2 weeks or when needed and do an enima (sp) once a month .. it's what works for me