Updated: Feb 10, 2019
How do you explain gluten or coeliac in a foreign language when sometimes, even people at home don't understand what it is?
This can is a bit of a challenge, so it is best to travel prepared.
It is a good idea to print a few copies of explanatory cards to take with you, and to show to the waiting staff / chefs to make sure your holiday and your health are not ruined by a "glutening"! The only thing to be mindful of is that depending on where you go they might have so many international staff in the hotel and restaurant industry that they won't understand your cards! That happened to me in a Japanese restaurant in Dubai. I didn't find anyone native to UAE working in the restaurants. The chef was Vietnamese, but thanks to WiFi we were able to pull something up online in Vietnamese to help explain. Normally it's not an issue in a sushi bar but the vinegar they used did contain gluten so luckily I checked.
There are websites that enable you to print off explanation cards in different languages.
There are plenty of others to choose from, and if like me you have more than one intolerance then you may want to look for another website with cards, or even consider making your own customised cards using google translate. Either way, be prepared before you travel. I find that a PDF or screenshot on your smartphone works too.