I had a very minor day surgery op, with full anaesthetic, just after Christmas. The hospital were fine. I was top of the list (one advantage of being diabetic!), and was told not to take my meds that day. I'm metformin only - it may be different if you're on anything else.
You should be called for a pre-assessment when they check your heart etc, and that's the time to discuss what they want you to do and make sure that the fact you have diabetes is on your notes. Ask as many times as you need to until you're sure both sides agree on whether you take your meds etc.
I was looked after superbly in the Day Surgery Unit (never mind falling passionately in love with the anaesthetist - wow
), and given a nice sandwich and some excellent coffee as soon as I was able to eat afterwards. When they wanted to check my BGs they let me do it with their equipment.
All in all I had a good experience, and I hope yours is too. Good luck to both of you!
Viv 8)