The best thing I ever did preop was to give up the addictive substances. I knew I couldn't have them after surgery, and getting past the withdrawal and cravings beforehand made recovery much easier. So, I gave up caffeine, all alcohol, all sugar, all soda, all artificial sweeteners, colors, flavors. I hadn't eaten wheat (gluten) for years, so that was not an issue. By the time surgery came around, I felt clean and detoxed. I did not eat the jello or popsicles in the hospital. I brought my own broth, herbal tea, and protein drink. Turned out they did have some great tasting gluten free broth that was fine.