I'm not sure which country you are in but in the U.S. it is standard practice to "put you out" for a colonoscopy. You simply go to sleep then wake up when it's over. It's not a bad procedure at all, the prep is the worst part (your colon has to be empty so you will have enemas at home and take medication to flush everything out of your system). Get on the waiting list NOW for a colonoscopy *AND* call your GP. There are simple tests that can be done for bleeding in the colon but you will need to have the colonoscopy - especially with your family history. Don't panic, my first one was at age 18. Nothing to worry about,.