She has taped my cat's jaw shut and has inserted a feeding tube in the side of his neck. Evidently, he has to stayed immobilized for 4 weeks with this taping. They are starting tube feedings by pureeing some KD canned food. The treatment you describe is standard for a jaw fracture.
Most cats tolerate the tubes well.
If not, a collar can be placed on their neck or head to decrease the chance of accidental pullling, or scratching of the tube. I am sure your vet will monitor it closely to keep it clean and make sure it is working properly. If you do not think they are watching it closely enough, have them visit with you about what to watch for and what to do if the tube should come loose. With the liquid diet in small amounts it is unlikely the cat will vomit, and the food picked would be appropriate for a cat with kidney problems. But if the cat should vomit, it should still be able to swallow , and redigest the food.