Did you have an event or something that spawned any kind of health crisis? Like dental work? Have you been exposed to heavy metals or something else that could have over taxed your liver?
Did you start following this diet cause you didn't feel good or have you been eating plant based for a long time?
Glad your getting Andreas' book, it's full of info. He was German and I believe they lead the field in holistic healing practices. When you do the flush, get some real olive oil from California, all the imported stuff is not olive oil, IMHO. The real stuff is said to heal or soften the liver, I beleive this.
I'm vegan but I had to add in some organic eggs to help my liver.