As a long time Chronie who used to travel a lot on business, here's some tricks I've learned:
1. Carry on extra underwear, TP and wet wipes. You'll probably never use them, but just having them helps the mind. If you think it will help you mentally, pick up some Depends for the trip.
2. Distract, distract, distract....whether it's reading books, magazines, doing puzzles, listening to music, playing hand held games, knitting - whatever works for you at keeping the mind busy with other things besides panicking.
3. Work out the no-bathroom times in advance as much as you can - i.e., how long to the airport, how long in the rental car bus to the parking lot, how long to the motel, etc..., sometimes just checking my watch and thinking 'OK, now I'm only 20 minutes away, I can make that' helps me to relax.
4. Don't be shy about asking a cab or bus driver 'how long will this take?' or saying 'I need the route that will give me a quick bathroom stop'. Learning as much as you can about the unknown routes before you step in a vehicle can help control the mind.
5. Don't eat until you feel 'safe'. This has probably helped me more than anything....not eating OR drinking a lot until I'm where I want to be. I'll even stop eating a day or two beforehand, or try to clean the body out beforehand. If nothing goes in, nothing can come out.
6. Have your doctors make lists of your medicines on their prescription pads or letterhead. Keep all your meds in their original medicine bottles even if it means taking dozens of bottles and of course, carry all this on. Keep a supply of all your 'emergency' meds in your pocket and have a bottle of water handy.
7. In Mexico, only drink bottled water, don't drink any drink that has been opened already, don't use ice cubes, avoid foods that may have been heavily washed in water and not cooked (like lettuce, tomatoes, etc), although the better resorts do work hard to make sure tourists aren't going to get sick from their food. Don't eat anything from the local street vendors. I've been to Mexico many times now and I've never been sick, but, I am careful to stick to the finer resort restaurants.
8. I agree with others here who have said that the 'thinking about it' is much worse than actually doing it. Once the day arrives, you'll be so busy you won't have time to panic, so until then, try to visualize having a great time. Also, try asking yourself 'What am I really panicking about? - getting sick? not making it to a bathroom?' Try to think of ways to make those panicky worries seem silly, because they are. Isn't it kind of funny how Chronies worry about having accidents in their clothes while most people worry about the plane crashing....???
DX: mild to moderate Crohn's for 34 years
Additional benefits: chronic anemia, B12 deficient, peripheral neuropathy, facial mylagsia, joint pain, underactive thyriod
Current meds: Colozal, Nexium, Entocort, Flagyl, steriod cream, monthly B12 injections, Neurontin, Synthroid, Effexor ER, pain meds as needed