A CT scan. But the problem is that it cuts both ways. Maybe I should introduce a little bit more about what we call a CT colonoscopy.
A CT colonoscopy is a special CT scan protocol, designed to look at the colon. By doing so, what this means is that you do need to get a full bowel preparation done. For those of us who were hoping that the CT colonoscopy avoids having to go through the horrible process of running to the toilet, unfortunately, that’s unavoidable.
And you’re absolutely right to say that a CT scan poses a much lower risk of perforation than a colonoscopy. But let’s bear in mind that a colonoscopy’s perforation rate is actually only about 0.1%. So we’re talking about an already very low percentage that you’re trying to bring down lower.
A CT colonoscopy has an accuracy that approaches that of conventional colonoscopy, but there is one very big limitation -- which is that you can see the lesion and what’s going on but unfortunately you’re not able to take it off and therefore you’re not able to look under the microscope, which is the gold standard to diagnose anything.
What your CT will show you is it says that you look like you have a polyp somewhere in the colon, in a particular region. But otherwise, that’s all it can comment. Does the polyp harbour any cancer in it? Is the polyp whichever subtype? We don’t know.
As a result of that, if you do have a positive CT colonoscopy, you’re going to end up needing a conventional colonoscopy to take out the polyp and let you know what’s going on.
