Whatever has been wrong with Steve, it must have been pretty serious for him to take so long recovering, either from it or from the treatment he's been receiving.
I don't want to speculate too much, but if it was a bladder issue he had, maybe bladder cancer? I know that's a reach as we don't know for sure, but my dad's had bladder cancer and he's been able to have the cancerous tumour operated on and removed, but recovery can be a week or two.
With Steve it seems he's been in and out of hospital, and his last op was said to be a short recovery period. It does seem very odd. We will likely never find out, at least not any time soon, but I remember he had bladder issues and it sounded familiar.
My dad also had issues a few years back with prostate pushing on the bladder, so maybe it could be something like that rather than the c word. Is it just me or did it all start after he said he had that health shot he bought which contained ginger, which made him violently sick? It seems ever since then he's been having issues.