One thing I've recently learned from my wife's experiences is that there are facets of gluten intolerance that go beyond Celiac disease, too. Some people have gluten allergies, leading to typical allergic responses (sneezing, inflammation, hives and/or anaphylaxis). My wife has recently (last 5-10 years) an inflammatory responses that last year she identified as the result of gluten consumption. What she finds is that she doesn't have to be ultra-scrupulous about excluding gluten from her diet, but by avoiding the consumption of any significant quantity, she avoids the muscular pain and swelling that had plagued her for years.
Celiac disease is a miserable condition, though. It's caused by gluten-induced perforation of the gut, which in turn leads to bleeding, cramping and all the other symptoms. I've only known one person with it, but she had to avoid anything that had even the barest trace of gluten in it.