I'm from Sydney and was diagnosed with coeliac disease in 2009. I love travelling and I love trying new and different food - giving up some of this has been the hardest part of going gluten free for me.
Balsamic vinegar does not have gluten in it. The only vinegar that is a problem is malt vinegar.
My 'glutened' symptoms are very similar to yours. I always get a massively swollen stomach and cramping.