I had the same thing happen to me and I got the same response. When I finally got to have it done properly I was told that I had a large polyp that could have caused the blocking and not allowing me to empty all the way. I to did the prep to the letter with the same outcome. I don't know who these people are. Do they really think that we would drink some of that stuff and not empty completely intentionally just to have to do it over again. I swear some times I think they don't have a clue. Do not stop and accept no answer or allow them to tell you you did not do it right. My last visit when they told me there was nothing that they would do for me and that they would not give me more medication, as if that is all I wanted, I spoke almost to the top of my voice and told them exactly what I thought. I have never done this before but after a while of being shipped here and there and nowhere to find nothing out, I WAS MAD and I let them know it. It did not get me answers but what it did was let the whole waiting room know how they treated me and I was encouraged to go to a whole new facility which I have already gotten farther with after one visit than I have in months with my old one. You know your body even better than them and just don't stop until all your questions are answered.
Oh you poor kid! I've had numerous colonoscopies, and twice the colyte didn't work. At least, not soon enough. Once it happened while in the hospital for the prep, and the nurses were just freaking because I drank it all down and NOTHING happened. It was awful! I was so blown up and miserable, and then in the wee hours of the morning, the nurses came in with the enema bag. Oh Lord save me now!
So no, you are not alone. The next time it happened was on an outpatient basis, and the doc just had the techs adminster an enema while I was out of it and I didn't have to know about it. Suction is a wonderful thing sometimes. :-)
Some docs just refuse to continue with the scope if even the tiniest spec of stool is left behind. You may just have a really picky doc. You're right about the staff. You had a valid question, and they shoud have addressed it. When you have your follow-up appointment with the doc, make sure you ask him directly. There are also alternative preps to drinking the gallon of colyte that may just work better for you.