The sources I used to create the allowed food lists for the FODMAPS elimination diet suggest that in clinical practice rye seemed to be reasonably well tolerated and is not considered problematic, although it does contain fructans. A more recent publication by the same work group puts rye on the "problem" list (Gibson PR, Shepherd SJ, Evidence-based Dietary Management of Functional Gastrointestinal Symptoms: The FODMAP Approach. J Gastroenterol Hepatol 2010;25(2):252-258). This is creating some confusion, and a lot of questions from sharp-eyed readers and dietitians!
After doing some extra digging around, I conclude that this is an excellent example of the importance of cultural context in In the US, for example, rye consumption is rare and in minor quantities. Even most rye breads in the US have more wheat flour in them than rye. This makes rye not "problematic" here, as in Australia.
In Scandanavian countries, on the other hand, rye may be eaten daily, and in larger amounts. According to a paper I recently read (Karppinen S, Dietary Fibre Components of Rye Bran and Their Fermentation In Vitro, VTT Technical Research Center of Finland, 2003) rye is the number one source of dietary fiber in the Finnish diet. That paper also reports that the fructan content of rye is significantly higher than that of wheat (typographical error corrected 8/18/10). Put those two facts together and you HAVE got a problematic food, at least in some parts of the world.
Looks like rye should be removed from the allowed food lists for the basic elimination diet, and added to the fructans challenge list. When all is said and done, most people will be able to eventually include rye in their diets in small quantities.
Remember, rye contains gluten. People with celiac disease shouldn't eat rye at all, even in small quantities.