Was the vet sure it was stasis and not an obstruction? If he was eating and drinking but not pooping, it could be an obstruction (symptoms are like stasis), and the only way the vet would be able to tell is with an x-ray. [oops nevermind I see that you said he pooped a few times today]

Will he eat any veggies? Maybe try putting the pellet slurry on a plate to see if he will lick it up since he doesn’t like the syringe?

Oh no, how scary
In America they sell critical care on Amazon
And Sherwood sells a “critical care” as well

If he is eating hay well and drinking, he is already doing what is best for him. Fibre and fluids! Put out bowls of water too, if he normally just has a bottle.

I wouldn’t be concerned at this point that he’s not wanting pellets. When my rabbits are not doing well, they go off pellets first and it’s the last thing they come back on to eating once they’re recovered. They know their body needs fibre. Definitely encourage wet leafy greens. Dill and carrot tops can be useful for a rabbit with an uncomfortable tum. Also try other forage type plants like rose, apple or willow leaves. Fresh grass if you can source some from an area you know isn’t sprayed or has wild animals pass through it.

Getting him moving around will help mobilise the gut also. So just changing up his habitat or putting some new hidey boxes in a free roam area. Or making a maze or obstacle course for him might get him curious enough to go investigate. Even simply putting him in a room he normally isn’t allowed in should get him moving.

Aw, he’s a darling with his little white sock.
I hope he continues to improve.
I know how stressful it is. My bun has been like this too and only just coming back to eating hay and toileting more frequently. I ended up taking her to the vet after deliberating a lot whether i should or not. Im glad I did.
I imagine you feel some relief for having Percy checked also.

Glad he is improving. Sebastian had Stasis a couple weeks ago. It was horrible, more for me than him! I was a nervous wreck, and as you have found out, giving a rabbit a syringe is like wresting an alligator! It was a two man job for me: one to open the mouth and shoot it in, and the other to wrap him in a towel. Thank gosh he is better now and is back with his wife, Juliet. I hope he feels even more back to himself soon, and I love that little white patch on his paws.