I was just in Italy for two weeks and did not see a single menu with gluten-free labeling, was not offered rice pasta at restaurants, and did not find any cookies or crackers that were gluten-free, as mentioned previously in this line of posts. Perhaps this is true in other cities, but I was in Rome, Florence and Venice.
However, it was a fantastic trip and I stayed perfectly healthy, but if I were someone who had to also avoid dairy I would have had a much harder time. My diet was mostly:
Breakfast: protein bars I brought with and yogurt bought from the store there
Lunch/Dinner: some combination of roast beef, potatoes, green salad, risotto, caprisi salad with tomatoes and mozzarella, cheese, fruit salad (I tried to order chicken and steak a couple times but it was coated in flour and they didn't seem willing to make it without)
Snack: gelato--in a cup
In all, I ate a ton of cheese and sometimes counted a latte, apple and a protein bar for lunch on the go, on days when my husband was content with a ham-and-cheese sandwich from a deli. Having a mini refrigerator in each hotel was definitely a plus.
The MOST helpful thing was writing out on a card, in Italian, that I was allergic to wheat, barley, rye, etc. Having this to read in their own language, the restaurant servers always took it seriously.