Hi,
Poor you they gave me two sachets of that gloop when I had mine I'm sure one would have done the trick! I was in the bathroom hours but the goos thing was I was so tired the next day when I had the colonoscopy even though I was supposed to be just sedated I was so far out of it I couldn't remember a thing. It took ages for them to bring me round lol.
Best of luck I hope all goes well for you.