According to Wikipedia coeliac disease is ‘also spelled celiac disease, is an autoimmune disorder affecting primarily the small intestine that occurs in people who are genetically predisposed’.
It’s not an allergy to wheat or gluten, although I must confess I don’t always correct people when they make this mistake. In my experience if a chef thinks you are allergic to something they are less inclined to feed it to you.
The autoimmune reaction caused by eating gluten when you are lucky enough to have coeliac disease can at best be unpleasant and at worst bad enough to require serious medical treatment. Prior to my diagnosis I was rushed to hospital after dialling 111 with heart burn so bad I honestly thought I was having a heart attack.
Coeliac disease is (thankfully) a disease that can be fully managed by sticking to a gluten free diet.
In the U.K. something is legally gluten free and can be labelled as such if the levels of gluten present are less than 20 parts per million (ppm). Gluten is commonly found in ;
Or brows for short.
The confusion can arise if a product has one of the above listed but is also classed as legally gluten free (due to the levels of gluten being less than 20 ppm therefore considered safe for coeliacs to eat)