Hello Erika
I don't know whether you've had your trip abroad yet. If you have, I hope it went well.
I agree with everyone who replied to you. I've had my colostomy for 10 years and had a defunctioning 'loop' ileostomy for 4 years before that. I've flown regularly, but not longer than 11 hours and I've never had a problem. The only bit of hassle I had was my first flight to Florida to visit friends after 9/11. I'd forgotten about scizzors, and had them in my hand luggage. My hand luggage and supplies were searched (in private) and the scizzors put in a box, labelled with my name and checked into the hold. When I told them that I needed access to scizzors to cut my bags, they made an arrangement with the cabin crew, so that I had access to their's if needed. Each time I've flown since, I've pre-cut them.
Just one thing, Virgin Atlantic have often let me sit behind the bulkhead, which gives you loads more leg room and I don't feel scrunched up as can happen in the rest of economy class. If I don't sit there, I take an Isle seat, so that I have ease of access to the loo if necessary.
If you haven't already been, I hope you enjoy your flight.
Best wishes
Richard