Here's novel concept. Liquid in = liquid out.............
If you are juice feast/fasting and not taking in fiber what the heck did you expect???? When you fast on liquids and your system empties any solids where do you expect solid matter to come from?????
Generally speaking if you are passing solids after the 1st coupla days on a juice fast it is a good indication that you bowels are congested and that it would be a good idea to do some colon cleansing. Many juice fasting protocols advice daily enemas. Personally I don't resonate with the idea but then again I have been regular my whole life. My personal choice is to adhere to the alternate protocol used in The Master Cleanse
of doing an herbal laxative tea before bed and salt water flush 1st thing in the morning on an empty system to get the toxins released on a liquid fast out of the system.