Just an update
I had the biopsies done yesterday; it went well enough.
I was told on the information sheet that I would be given pills to take 24 and 48 hours after but I was given Gentomycin by injection just before the procedure instead; they told me the information sheet was out of date.
Very light-headed for about half an hour afterwards but it mostly cleared after a cup of tea and biscuit. They don't subscribe to the warnings about dairy products and Ciprofloxacin so I got milk in my tea.
What was significant was that they told me that they would not do the procedure if I intended to drive home afterwards; that my insurance company would not pay out if I had an accident and they found out about the procedure.