Have to agree with Nanners, anxiety is what can really kill a trip. My Daughter who is an 11 year IBDer and a fan of long distance and international travel does pretty much the same as Nanners.
She takes 1/2 dose of Ativan or Xanax before long distance travel and full dose if she will be flying many hours internationally. She also goes with a bland diet 2-3 days before traveling.
This girl has traveled in some less than prisitine conditions especially in South America. Long, hot, nasty bus travels. Good to have immodium on hand just in case. Anti-nausea med is good too.
Bottled water always.
Don't forget to pack your prescript
ion meds in your carry-on in their original containers!! Can't trust the airlines these days or the peeps checking through your luggage.
Happy travels to You!