HP, did they say why they wanted a cat scan within a week? Did they see something that concerned them? Please ask what is going on, you need to know. Don't let me scare you though, I know nothing of what is normal here. Just seemed to me that there is an urgency and I'm reading between the lines. I also noticed on the website I referenced that they mention a "virtual colonoscopy" as one of the capabilities of the cat scan machine, so my thought is that they might have seen something that they want to get a better look at. Let us know what you find out. I am praying for you.