Sorry to here your colonoscopy was a bad experience. As for the swelling and stomach pain the nurses should have told you at some point that air will be used to open  parts of the bowel wall to accommodate the scope around the bends in the colon. this air will make you feel bloated and give you tummy pains until at some point you pass wind, which will make it easier for you.

I would say any blood you pass will be from polyps that have been removed this stops quite quickly. being in there for an hour is a long time for a colonoscopy. Depending on how many polyps have been removed and sent away for biopsies. My last colonoscopy I had in May, and I'm still waiting on the biospsy results. I finally got a report on what was in my colon I had 8 areas which had polyps removed four in total each was 5mm. and on my report there was something they called flat polpys 30 in all, to many to remove, so  I need a follow up to keep check as they could not say if they were cancerous or not..  due to me having to go on a 12 hour fasting, I was already in hospital with high temp, and what I know now to be gall stones. the fliud I had to drink yet again made me throw up. this in turn gave me 4 hypos while I was there. The hospital I can not name as it breaks forum rule ( thank Ben ). they said another way was a small camera the size of a tablet you swollow  and it gives images of the oesophagus and bowel till it's passed out. it's got to be easier than having to drink 2 litres of movie prep and then bringing it back up. Sorry I went on a bit. but if it helps to give someone an insight to what happens if it's someone first colonoscopy. then at least they will have some knowledge. one thing I will not do is glamourise any procedure.