Don't rush into travel. Wait until you are fully recovered before taking your first post-op plane ride.
Attach a fresh ostomy bag just before flight time. This will keep you more comfortable, especially if there are delays.
Pack extra supplies and keep them in your carry-on luggage. Write down your product numbers and keep them in your wallet.
Gas in ostomy bags expands with altitude. As the gas in the intestinal tract expands, the stoma's output of fecal matter and gas will also increase. If you have to take the bag off while flying, beware of fecal overflow.