So sorry to hear that your Dad is going through this. Sounds like it's such a discomfort for him to get anything down. After a while of not eating, one's appetite for anything seems to fade. Would some sort of liquid nutrition be an option? i know there are some healthy meal replacements out there that may trigger his appetite again. I'm not sure if he can drink it slowly or not. Perhaps a nutritionist can suggest some options for easy swallowing and digestion. I've even heard of baby food being used to help with getting back one's appetite slowly and with ease of swallowing. I'm not a medical professional and not familiar with your Father's condition. I would suggest posting these questions in the Nurse's or medical professional forums to get their input. Best of luck and best wishes to your Father.
Im sorry for your dads condition, unfortunately it might take some time maybe even some therapy to learn how to eat again.
Have you tried taking solids out of his diet? Perhaps soup and liquids would be the best way to go right now. I'm sure after gaining some more strength he will be able to eat, but like i said it can be a while, until then they a healthy liquid diet....
Much Love, Lexis