your friend's circumstance seems similar to mine except alot worse. my kidneys are aching quite a bit - especially when i lie down at night. i think the aching is due to the Liver Cleansing diet i am now on. maybe both your friends and my kidneys were not in good shape prior to the liver cleanse, and the liver cleanse has put quite a burden on the kidneys.
maybe people should only do a liver cleanse if their kidneys are up to it(?)