I understand your frustrations as I was there last year but there is no easy answer. When a cat stops eating for a few days, the liver gets affected and drops the appetite even further. Appetite pills can help but are not a cure-all. This is where your relationship with the cat will become extremely important. A vet may be able to force a cat to eat (feeding tube and such) but only the cat's human will be able to convince the cat to eat. It took me over an hour twice a day to get mine to eat when she was sick. I literally fed her a dab of baby food on my finger at a time. I would get her to lick a few dabs and then try again 5 minutes later. And of course, you have to have the right mindset when approaching. Going near him with the "Dang it, eat already!" attitude will get you nowhere. My husband lacked the patience to deal with this and would get frustrated quickly so I was the one to deal primarily with it. This forum was my lifeline - not just for advice but also a place to vent. I sincerely wish you the best with this.
He takes the syringe feeding well. He doesn't run from me and seems to know it's good for him. But it's still a hassle chasing him down and I feel like a bully having to hold him and be forceful. He at least doesn't seem to resent me for it, though.
I've got a full can of high calorie special food and a can of Turkey baby food down in the past 18 hours. (I mix the two for a less viscous consistency for the syringe.)
I have a great relationship with my cat. If anyone can do this, I can. He trusts me implicitly, feels very comfortable in his home, and is still probably getting over the trauma of the blockage.
I closed him in his room with food. That's worked in the past when he wouldn't eat -- as opposed to leaving it out in its regular spot in the kitchen. Taking the distractions away seemed to help.
If that doesn't work, I'll go back to the vet for more high calorie food and keep at it, I guess.