Take an Immodium before you go. Don't wait to see if you are going to have problems, then take it. For some people just knowing that they took it lowers the stress and helps to prevent an attack.Also avoid any known trigger foods during the days leading up to the flight.Also you probably want to avoid foods/drinks that are known to cause diarrhea, even in normal people.These are:Alcohol, caffeine, fruits containing sorbitol (apples, pears, prunes) and sugarless gums and hard candies with sorbitol. Dairy (unless you are clear you tolerate lactose well) Things with high fructose corn syrup in them (most of the sodas, and some fruit beverages). Check the ingredients of herbal teas you drink make sure none of them promote regularity, or are laxatives.Hope you have a wonderful trip.K.