Sorry to hear about your father in law.. i lost my dad two years ago, and yes it's not easy.. in fact just the psychological stress of it made me even sicker, so please take care of yourself..
Regarding the burning -- I've found that doing a Colon Cleanse the day of the Liver Flush makes the whole thing go much easier - I don't get any burning anymore, and everything comes out clear so it's easy to see what you're eliminating. I also find that if i do the Colon Cleanse i get diarrhea the day of the flush, and if i dont do the Colon Cleanse i only get the diarhhea the next day, lots of it, and lots of burning.