I had both done at the same time (they kept referring to me as "the patient getting the "double""

)
I agree with what has been said -- it is "twilight" anasthesia, but the vast majority of people don't remember a thing! It's like you've been asleep through the whole procedure. I do remember some of it near the end, when I was in pain from the air they put up in there

, but I think that's kind of unusual (they had a hard time sedating me, apparently). My memory of it is not really that traumatic, because I was so out of it at the time.
The prep is horrible, horrible, horrible. Follow other people's tips to get through it. I like the tip of using mouthwash to swish the taste of the prep away. I actually had a big bowl of beef broth (I know

I would never drink it normally, but somehow hte strong saltiness helped take away the nasty taste of the prep!).
Stay near the bathroom. Near the end of it, you will be basically pooping water

gross!!! It literally feels like you're peeing from your butt. Don't mean to be gross, but it is exactly the feeling of emptying yoru bladder, only from the wrong hole!!!

Near the end, you'll want to be really careful about walking away from the toilet or doing anything that could impede you from getting to the toilet ASAP! If you feel a tiny tiny cramp or feeling like you might need to go soon (one so tiny that you would normally ignore it), RUN, don't walk, to the toilet!! You will have no time to spare!