I have had the ct scan colonoscopy the bowel prep is the worst bit. The scan involves an injection the back of your hand that makes you feel as if you have peed yourself, you don't it just feels like it. No discomfort in the bowel at all so pain free .They found bilateral ovarian cysts  on my scan that they have removed. I hope that helps to relax you at the thought of your next scan. 
take care 

Susie 

Thankyou susie for replying.hope your cysts were benign. The scan you had is that the virtual one? Did they put camera up you like the colonscopy? Sounds like your scan was def pain free x

Thankyou susie for replying.hope your cysts were benign. The scan you had is that the virtual one? Did they put camera up you like the colonscopy? Sounds like your scan was def pain free x

Fortunately the cysts were benign the operation was a bit difficult due to multiple adhesions the surgeon stuck with it spending over 4 1/2 hrs clearing them. It took a while to get back to normal. You may feel the air when they inflate your bowel but it was not uncomfortable. Much easier than the other colonoscopy. My doctor said they are now locally doing most of the colonoscopy scans by ct. lt seems to be making the list shorter as l was seen within ten days. 
susie