Welcome aboard, John! I hope you are recovering well from your surgery, and I'm very glad to hear that you'll hopefully be able to enjoy more solid foods again by the time your magical cruise date arrives! Perfect timing, because you will really delight in the wide variety of food options offered with Disney Cruise Line.
When guests have specific dietary requirements, it is always a good idea to add that information to the reservation in advance of the sail date. I recommend that you give the agents at Disney Cruise Line a call at 800-951-3532 to add a note to your reservation detailing your dietary restrictions. Of course, you're welcome to discuss that with your servers onboard, and go into further detail then too, but it's helpful to have the information in advance as well.
Since Disney Cruise Line features
Rotational Dining, where you'll get to experience all three of the main restaurants throughout your sailing, your servers will rotate with you. That means that once you meet them and discuss your needs that first night, you won't have to re-explain to a new server each night since your servers will be meeting you again the following night at your next restaurant. Dietary needs or not, it's a wonderful perk to sailing with Disney. My family loves getting to know our servers, and they really do become like family by the time we finish our cruise. We've sailed many times and have had absolutely amazing servers every single time! I know you'll find the same!
I hope those details help as you continue planning! Enjoy your cruise!