Have you tried the compazine suppositories? There was a while when they were the only thing that worked for me (even though I hated how totally out of it they made me). If you have tried those, I don't know what else to suggest except that if he really can't keep his pain meds or food down, and it's been days, he probabl;y should go back to the hospital so they can give him IV meds and liquids and nuttients.