Hi, I've had an ileostomy for quite a long time now and coping with it as well as anyone.
When I got divorced 10+ years ago, I worried that my sex life was over as no one would want to sleep with someone like me with a bag stuck on their stomach. I was feeling a bit down and felt sorry for myself.
My approach was somewhat different to what seems to be the regular advice given here.
Initially, I ventured into the strange unknown world of massage parlors, and discovered that Manchester, not too far away, had an abundance of them. Lacking in confidence, I was initially apprehensive about entering one of these establishments, but finally took the plunge. The ladies I met were very welcoming, most saw the elasticated belt I was wearing and immediately guessed what it was covering, telling me they'd had many clients with a bag before and not to worry. It may be looked down on by some, but it certainly picked me up at a time when I was feeling pretty low and needed picking up.
Reassured that such things were still possible for someone like me, my next step was speed-dating. Initially nervous and embarrassed to be there, there was absolutely no need to be, as everyone was in the same boat. Over the next couple of years, I went numerous times, only actually paying the first time. After that, the organizer would ring me up, usually on the afternoon before one of his nights, saying he had more ladies booked than men, would I like to come for free? This tactic then enabled him to accept more paying ladies. It seems there are more mature ladies wanting his services than mature men. Who was I to complain?
I did also try computer dating, but I much preferred speed-dating, where you at least had 5 minutes face to face with someone before arranging a date, so had at least an idea of what to expect.
Every post about 'when to tell' says to discuss it beforehand. Quite honestly, I have never done that. Quite the opposite in fact. Each new relationship I have had, the first time we had sex was exactly the same as if I did not have a bag, and I did not mention it. I would always make sure the bag was empty, and held firmly in place by an elasticated belt, (usually a hernia support belt supplied free by the NHS). I now have several in various colors to match what I am wearing.
First-time embarrassment maybe, but none of the ladies ever said a thing that first time. Then, on the second or third time, I would be asked why I was wearing the belt. I would brush it off by a casual 'Oh, I had an operation there a few years ago, nothing to worry about' and ended the discussion. Usually the next time, I would be pressed for more information, when I would answer the question, but without going into too much detail. Eventually, I would go on to explain fully, but by then we would probably have slept together up to half a dozen times, so there was no need for me to say anything about it not affecting me in any way as they already knew.
Also, in a way in which I didn't so much when I was younger, I always went out of my way to ensure that she enjoyed herself fully, and wanted to do it again. Looking back, I was a more selfish lover in my younger days. Had I tried to explain before we had actually done it, I think we both would have found it embarrassing. Waiting until after, she knew fully what it was like, and exactly what to expect from a relationship with me.
Admittedly this is from a man's perspective, so I cannot say it will work the same way for a woman, but when it comes to first-time sex with a new partner, confidence is the key. A confident woman, with her empty bag covered by a suitable sexy suspender belt should be able to steer her partner's hands away from her bag without going into intimate detail about past surgery. The new partner will probably be too unsure to ask too much on that first occasion. After that, he knows enough of what is possible for him to then be told a little more if you choose.
As I said at the start, not the usual advice, just what has worked for me.