Ileostomy vs Colostomy

Judging from your other post, it's going to be a temporary diverting ostomy to allow your fistulas to heal.

An ileostomy would give your entire colon a break. Not sure how much this matters. I'd be inclined to go with what your surgeon recommends. Have they said why they prefer an ileostomy?

It sounds like it'll be an end ileo rather than a loop one, which is easier to manage - just make sure your surgeon knows the importance of creating a decent spout. Half the problems people have with stomas are caused by the opening being too close to the skin.

And yeah, you can bathe/swim with an ileo, not sure why you think you can't. I dunno about exercise - it tends to be an activity I go out of my way to avoid. I do know that there are bodybuilders with ileos, though, so weight lifting, etc. is possible. Probably not advisable for the first few months after surgery while your abdominal muscles are still healing though.

If you're thinking of having a permanent ostomy, then that changes things slightly. Me, I think I'd be too nervous about the Crohn's coming back in the rest of my colon if I'd had a colostomy (it was never an option for me, as my whole colon was affected). But otherwise, all things being equal, a colostomy is probably easier to manage than an ileostomy.

But ileostomies are pretty piss-easy once you get used to them and your bowels have adjusted to their new plumbing - this can take up to a year, although it's not like you'll be emptying the bag a zillion times a day before that. For the first year, I was needing to get up once in the night to empty the bag but after that I was able to sleep right through without needing to get up once. Emptied the bag about 4-6x a day. It's probably a bit easier for women, 'cos they're always going off to the loo to take a pee anyway - men don't so much. But that said, if you have Crohn's you are probably already used to frequent toilet visits.

Technically you can have a diverting ostomy forever, but you don't really want to leave a defunct colon in your body for 10 years. It's not a great idea. There's a high probability of developing diversion colitis for a start. It's not as bad as Crohn's, but it's still inflammation and it's still not particularly healthy.

My biggest concern at the moment is dehydration with the Ileo.

Meh, not a problem at all, unless you run marathons in tropical heatwaves or whatever. Your small bowel learns to behave like your colon to some extent; that includes absorbing water. People without colons are slightly more prone to dehydration, but not enough so to worry about. The only time I remember getting properly dehydrated was when I caught norovirus - the combination of diarrhoea and vomiting was pretty brutal. Still, I got through it without needing to go to hospital.

Diversion colitis happens when stool is diverted away from the colon. The colon doesn't like being deprived of its 'food' and becomes inflamed as a result. It's usually not serious and usually goes away once the bowel is reconnected. I say 'usually', 'cos I suspect people with IBD are a different kettle of fish. I had diversion colitis in my rectum and it didn't go away after my reconnection - it just got worse and turned into Crohn's disease. (Or else it had been Crohn's all along. I was told I had diversion colitis and that it wasn't Crohn's, but who knows what it was really - apparently not my doctors.)

Diversion colitis takes a few weeks or months to appear, I think. In my case it took a few months for the symptoms of it to develop - mainly passing of mucus, but also of blood occasionally. Plus rectal soreness and cramping.

I stopped my meds entirely. There wasn't a single one which had worked for me apart from pred anyway; I had to taper off the final 10mg of pred very slowly because I'd been on it for so long. I remained in remission for as long as I had the ostomy, which was about 2 and a half years.