Hi, I found the exact same problem. Not having read the book, or the recipe carefully enough, apparently, I decided on my next flush I was going to drink water with the es.
What a great help it was. In fact, many times I would drink the water and only then suddenly have to "go". I attribute this to my body desperately hanging onto water that my bowels were demanding. Thus I felt horrible and actually didn't go to the bathroom easily, until I drank the extra water.
So, from my own experience, I would highly highly recommend drinking water along with the es.