Regarding discomfort all I can say is what I feel. I get nausea about 3 hours after taking the oil/juice mixture that gets me running to the bathroom not knowing which end it'll come up! So far it's always resulted in a bowel movement that contains stones followed by an immediate cessation of the nausea. speaking to others and from my own conclusions I believe raising the head at night will help this as it will prevent the oil glugging back up into the stomach. The answer then is more pillows!
Regarding liver stones , I think I'm correct in saying all stones are formed in the liver and just work down into the gallbladder like a conveyor belt! The reason we only hear about GB stones is because they're the only ones you can see on ultrasound( the calcified ones that is). There is plenty more on this subject on the liver cleanse page.
There is also plenty of info on kidney cleanses on the kidney cleanse page(funnily enough!)