How Can Stage-4 Kidney Failure Be Treated?

Just what is kidney failure? My best friend has been told by a kidney specialist she has kidney failure stage 4 and the doctor has merely told her he wants to see her again in six months, and did not give her a list of things to eat and some to avoid. She is coming to my home on Thursday and I am to be prepared to give her some guidance to keep from further damaging her kidneys and hopefully to improve the prognosis. I am a firm believer in cellular detoxing daily with Living Clay, as it literally sucks out the what enzymes she should be taking that would enter the cells and strengthen her kidneys. I was looking at the list of fruit and veggies to avoid and it is stated to avoid high levels of potassium, and I think that is good advice across the board, and even for me who has had open heart surgery. However our bodies need a certain amount of potassium which is governed by the amount of magnesium we take, is it not? I do not know the terms and conditions and cannot accept them since I do not know them. If there is a fee for this consultation, I shall continue to do this research independently