Well I did no bending or lifting or twisting for a year. And by no lifting, that meant almost no lifting of things at all. I was careful because I know of a guy who basically wasn't careful and his fusion was all messed up...and at that point I was told there is really not much they can do for you. I had a disc removed and they put bone in there, which had to grow and fuse the vertebrae together (along with the titanium hardware).
So, they get you up and walking basically right away, but it's a major surgery and you're both tired and feeling it. I started with little 3-5 minute walks after the hospital and progressed from there. I think I missed about a month of work, and a chunk of that was that I wasn't able to drive or things like that.
I would say they didn't do a great jo of preparing me for what to expect though. I read things online about having to be able to live on one floor (no stairs) and things like that. I was definitely worried about how this would go. I did find stairs difficult, but you could manage. You just had to literally go up a step at a time (or down) and kind of get set before the next. It's pretty debilitating, to be forthright.
But good news, it totally worked for me. I'll always have a sore back, and really that's just what I expect. But I can swing a golf club more times in a round than I would like (
) and I am totally active and doing everything I could before. I had stopped a lot of activities prior to the surgery because it was just too difficult. There's a mental toll that takes as well and I'm sure that your brother is dealing with that as well. But, things get better and with some patience it's a world of difference!