It seems that her 'running out' is more about her insecurity than your ostomy. If one is not good enough with an ostomy, then why would you want to see them anyway?
I guess partly because of my age, I am completely comfortable. I tell jokes on myself - a loud noise waking me up, jumping up to see what was happening, and discovering it was a loud belly fart. I discovered that cauliflower, broccoli, and Brussels sprouts as dinner make a lot of gas, almost earth-shaking. I laughed out loud at myself for 5 minutes. I talk openly and even show it to anyone interested in looking. Curiosity often is stronger than judgment.
It is a pretty amazing lifesaving procedure.
I am sorry this happened to you but more sorry for her. It seems she missed out on a guy that seems really sensitive. I hope you return to dating. Others will appreciate you. If I ever cross the pond again, I'll ask you to show me around.