They will probably give him IV hydration at the hospital. It can easily be five hours just getting enough fluids into him. My personal observation is, while food is important, fluids are even more so while a patient is undergoing radiation. In addition, has he been given exercises to do for trismus? It’s important for him to keep doing those all through. One side effect of radiation for head and neck patients is trismus. Not being able to open his mouth can be a problem down the road. John needed a procedure that required general anaesthesia. Before the doctor could do the procedure, they had to consult the anesthetist to see if John could be intubated because of his narrower mouth-opening.