I don't think a scan is the solution but a biopsy by endoscope. I completely understand your concern. This would be done by your GI specislist anyway I'd imagibe and review would be very soon given your weight loss. Keep on his back. You are not being paranoid just sensible as you want the correct treatment.
Hope all goes well for you. It really sounds like a bugger of a thing and so bloody annoying to now have to deal with this. If I recall correctly it has taken them a while to figure this out.
Please keep us up to date. Kath x
