Hi Hil (and Rico),
You got a lot going on there sister... you're obviously quite a trooper!!! Way to go! Normal hospital stay for an ileostomy is between 5 to 7 days if they do it with open surgery. Laparoscopically reduces that by a couple days... and that assumes there's no complications. But some (most) surgeons want to do it openly to see everything they're dealing with. If they're doing you 'open'... I advise you get the epidural... it's a game changer... and you'll thank me the day they take it out... and ask them to put it back!
Rehab is usually only for home infusion if your situation warrants it... and then they come to you, not the other way around. But don't plan on running any marathons when you get back from the hospital, no matter what. It takes a good 2 weeks for the 'open' incision to fuse properly, and then get your stitches out. And even then you need to take it easy or risk a hernia or worse. You're getting a 4-week vacation whether you want one or not, so plan accordingly... and that means minimal exercise, if any at all. You're gonna be a hurtin' pup, so lay low and enjoy your downtime.
Also, do a little pre-planning. Figure out how you're going to sleep when you get back from the surgery. Recliner or bed? Back or side? Some find lying supine really problematic with a stoma, so the recliner might become your best friend for a week or two. Going up and down steps won't be fun, nor will riding in a car that hits potholes. Coughing and sneezing will have you thinking you've blown out your stitches many times over... so don't do those either. A lot of trivial things won't be so trivial anymore, or at least for the time being. No pets jumping up on you, wear old clothes you don't mind leaking on, etc, etc. And have plenty of ostomy supplies on hand. I mean like a LOT!! Most times the hospitals give you a box of bags, rings, and barriers and wish you good luck. But if you spring leaks... and you will since your stoma will shrink and things will settle... you'll burn through those supplies in a day or two. So have LOTS of stuff on hand to eliminate that stressor! Amazon's next-day delivery will be your lifesaver if not!
You'll also want to brush up on your wound care skills. Sealing the ostomy is one thing, but keeping your incisions infection-free... and dealing with those infections when they happen... is really important. So have those supplies on hand too. Sterile sponges, Tagaderm films, adhesive remover wipers... etc, etc, etc.
So the real 'back to normal' time really depends on your version of normal. You're FULLY back in about 6 months, but people push it... sometimes to their detriment. You'll get a feel for it as you heal, and when you screw up... you'll know it.
As for diet... wow, that's a big subject! From the ostomy side, it depends on how much bowel you have removed. Hydration will probably be your biggest problem, as you can supplement vitamins and minerals to replace what your bowels no longer absorb. Find yourself a really good IBD Dietician who knows their shit and they'll get you straight. There's so much info out there now about controlling and eliminating diabetes with diet that I won't even go there. You've got a lot of reading to do and YouTube and guys like Dr. Berg and Ken Berry will be your new best friends. Diet on the ostomy side is really about trial and error to see what your body can absorb and what it cannot. Everyone is different, so don't put too much faith in what works for someone else. Like I said... there's just so much to know about all this it can't be covered in a few posts. And while you have some downtime read up on how digestion works. That will key you into the cause and effects of what you do wrong, as most don't think much past the amount of output they have and their frequency. But things like the color of your stool keys you into how your fat absorption is working, and having loose watery stools is really overstressing your liver and gallbladder. Not drinking while you're eating will prevent your stomach acid from getting diluted and not properly breaking up the food for your intestines to absorb. If you know that stuff going in you'll be avoiding much bigger problems down the road that most don't consider at the time they get 'ostomocized'!
Lastly, the 'what you tell people' thing. This is already a book so I'll keep it short. It's a learning curve we all go through. Your comfort level will guide you... and then at some point you really won't give a shit who knows and kind of look back at what you were worried about and laugh. We can get you through all that easy-peasy. That's what we do!
It sounds like a lot to have to deal with... and it is. But it's manageable. Promise.
;O)