Betta Laying On Side At Bottom Of Tank

When I increased the water level in the tank Seb seemed more upright than he has since moving to the hospital tank. He also seemed to have a bit more energy, and even moved to get the bloodworm, rather than having to have it put in front of his mouth.
I've left the water at the higher level at the moment, and after I've fed the rest of the gang I'll go and spend some time in the spare room to observe Seb.
I had a bit of a moment earlier of not wanting to tempt fate, but thinking that perhaps his health has improved slightly. I guess we'll see how things progress over the next few days.

Good to read of this - Seb is certainly a fighter (excuse the pun, given that he's a SFF). Keep up the good work with him, @Littlefish.

Good to read of this - Seb is certainly a fighter (excuse the pun, given that he's a SFF).

That pun was unavoidable. 

I've just increased the water level to offer some bloodworm, which he took with enthuiasm.
Again, with a higher water level he was more upright, and was moving towards the bloodworm.
I've left him with the higher water level for a while, and he is upright, but still on the bottom of the fry trap. He is having a bit of a wiggle, but not actually getting off the floor.
He has had a course of esha2000 treatment, and I'm continuing with daily water changes. His tank is currently running at around 29C, and his colour is still good.
Do I continue with this, or put him through another course of ehsa2000, or try another medication?
He seems a lot more comfortable than he was a few days ago, and my levels of concern and panic are back to reasonable levels.

Thanks all for your support & good wishes for this little fella.

I would go with adding a couple of extra doses at the lower rate.

Sounds like good news. I would also be tempted to start to bring the temperature down a bit to more 'normal' levels... may be a couple of degrees over a couple of days. And maybe try him on some of his normal food too.

I've done a water change & medication dose.
I've also fed Seb 2 bloodworms.
Then I saw something in the fry trap that I thought was a small snail, and thought that wouldn't be good, so pulled it out with the forceps. It was the most massive pooh I've ever seen from a betta. 

Delighted to hear that there's been "an intestinal clearout" - let's hope this gets Seb properly back on the mend and back to his former self! Fingers crossed and keep us posted.

Unfortunately not.
I continued the daily regime of water changes, medication, and offering bloodworms.
He had a bloodworm for dinner last night.
I have just been to check on him, and I'm afraid that Seb (f.k.a. Handsome Boy) has passed away. 
It's frustrating not knowing exactly what was wrong with him, and I'm consoling myself with thoughts that he was in a more peaceful environment in the hospital tank, rather than having the panda corys constantly moving around him in the main tank. I'd like to think that he was comfortable, and he didn't seem to be suffering in the smaller tank.
It's still a massive disappointment that I didn't manage to nurse him back to health.
He was a very friendly and charming little fella, and I'll remember him fondly for the time he poked his head out of one of the holes in a piece of decor in an adorably expectant manner one dinner time. 

Thanks @Bazza2000
Sometimes these things happen.

I had been wondering how he was getting on but didn't dare ask. Absolutely gutted for you to read of this. Not that this will help with the upset and heavy heart you'll be experiencing for the next while, but you certainly did everything you could possibly have done for him and gave him the most comfortable end to his life that is possible - and I think he would have known that and was doing his utmost to pull through. The little story about him poking his head out expectantly one dinnertime actually brought a tear to my eye on reading it - he sounded lovely.