So far so good, he's been a good boy taking his tablets, and he ate his breakfast quickly this morning, so getting back to normal. One worrying thing is his urine looked very yellow in litter tray (I use the crystal type litter, so it's very noticeable), but I suppose if his tummy was upset previously this may be normal. He does seem fairly bright in himself, third eyelid has receded a lot, and he's a lot more vocal about being shut in!
Thank you all for your positive thoughts