I don’t have any personal experience, but I decided to search for you. Sometimes curiosity gets the best of me. Sometimes the search function doesn’t work but it did this time. I got a little carried away reading. I put the word bariatric to look and came up with many threads.
If this link doesn’t work try searching for it. Good luck with your surgery and the cruise.
https://boards.cruisecritic.com/search/?q=Bariatric&quick=1