My GI was considering one for me earlier this year, though it got hung up in red tape because provincial health insurance plans don't cover it. That being said, I have reservations about it as well given that I have a history of adhesions. I had an MRI enterography. Pretty straightfowarded, though drinking 2L of volumen mixed with metamucil wasn't exactly my cup of tea.
With respect to diagnosis, sometimes IBD can be indeterminant. Crohns can sometimes be tricky to diagnose because it doesn't always present classically. As Jan said, it's always good to have a working diagnosis to guide treatment. However, many inflammatory conditions have the same treatments despite differing diagnoses, so even if Crohns isn't confirmed or ruled out, chances are the course of treatment may be similar.