With the pain that continuos and intense you could very well have passed or still be passing kidney stones and or more calcified sediment. Keep drinking that water to flush things out and contimue cleansing till all pain and discomfort has passed to allow the system to expel those toxins and or stones.
Believe you me I know all about kidney pain and kidney stones. I was a frequent flyer ;+D It got so bad my system would go into evacuation mode and every orifice in my body wanted to evacuate. With all that evacuation and not even being able to keep water down I was hospitalized twice.
I do at least one 40 day MC each year and have not had any more stone episodes in the 9 +/- years since I've been MCing. I've reaped many other benefits but that's another story. Since it takes 2 weeks +/- to cleanse out the causative agents in your system it is after 2 weeks when the "real" cleansing at the cellular level "begins" I consider a 21 day MC to be the minimumworthwhile doing.
What the book does mention is "diarhea" and not just liquids coming out.