I've recently had a Colonoscopy and like you was shocked when i received the letter... My advice would be to have the procedure... I was terrified, 'beside myself', I've had several 'poo tests' and dreaded the result each time, probably more so now I am 73... There is no question that the preparation for the procedure is quite a saga and needs some thinking about (for me anyway as i am scared of anything medical')... my further advice would be follow all prep to the letter and if unsure don't hesitate to ring the number they give you as the folk on other end of phone are lovely. I have sent a thank you card to all the staff I had contact with, from the smiley woman at reception to the kind, caring nurse there for my exit chat as my care was exemplary, truly caring, kind, never rushing me and so understanding when i got upset. Its not a pleasant experience however it doesn't last long and you can pause the procedure if its too uncomfortable. I am so glad i had 'it' done... I cannot praise our NHS enough, it is truly an institution we should all be proud of... Finally our nurses need to be paid better they are AMAZING... Please have this 'done', you won't regret it EVER!!!