Well, now that I'm on the other side, I can report on my experiences with eating.
After breaking the Yom Kippur fast Sat. night with an omelete and rolls, I went to the hospital. My surgery was scheduled for Sunday at 2 pm (to allow my "partner" time for a last, heavy-duty dialysis treatment), and they told me to eat just before 8 am, which would be just before the 6 hour pre-surgical limit. When I said, "Oh, whatever, I'll just fast overnight and continue like that into surgery", the nurse said firmly, "No, that's too long. We want you to eat at least something before 8". Since the breakfast tray arrived after 8, it's lucky that a small slice of pound cake providentially happened to come my way just before 8.
On Monday, the first day after surgery, I ate some of the dried apricots and (unsweetened) applesauce I'd brought to the hospital (along with lots of prunes), and later drank a very small glass of prune juice. This was in response to countless posts about prunes helping avoid constipation.
But in the end, my stomach was sort of apathetic about the whole business. No constipation, no gas pains. Actually, if anything I ended up with a situation better suited to bananas or rice, but what the heck. I don't know whether having avoided the bowel prep had anything to do with missing out on the constipation, but in any case I'm happy with how things turned out.
By the way, after surgery nobody on the staff ever asked me a single question about any aspect of digestion. Certainly, it had nothing to do with my getting out of the hospital.
Finally, my discharge letter notes that my glucose went from 84 mg/dl on the morning of the surgery to 110 on the morning after (normal: 70-100), which I assume is due to the dried fruit I ate in trying to avoid the constipation.
Since I came home, I've been eating more normally. I'm never actually hungry, but I can eat when I have to. I'm paying a lot of attention to drinking enough water, and to avoiding foods high in sodium (ie, I've cut tons of foods out of my diet).
Your mileage may vary.
Be well, Snoopy