I hope your surgeries will be a great success and you’ll have a full recovery!
With that being said, reading your post, even under normal circumstances I’d say that anyone reading your post couldn’t possibly tell you if you could or should do anything, because the person in question would operate on very little information.
Even if we would know everything about your circumstances, general eating habits, average daily calorie intake, and average meal composition, we would still not have a clue about how that would effect post-op situations.
The only reasonable advice I could give is to discuss your IF with a doctor, like your surgeon and your usual doctor. The first because the surgeon knows best if IF would be a benefit or disadvantage in recovery and the second because your usual doctor knows your medical history.
I hope we’ll see posts of your successful recovery soon! ;)