The disorder is estimated to affect about 1 per cent of the world's population, most of whom remain undiagnosed.

Prevalence has been measured in a few countries in the Asia-Pacific region, but it is 'extremely rare' among Chinese, says Dr Wayne H.C. Hu, a specialist in gastroenterology and hepatology.

The disease develops as an interaction of genetic predisposition and diet, often Western, which has a higher content of wheat products. How early gluten is introduced in the diet at childhood can also be a contributing factor. 'It's predominantly a Western disease,' says Hu. 'There may be a few case reports, but from the patients that I see, I haven't diagnosed a single Chinese with coeliac.'

However, incidence of gluten intolerance might be on the rise in Asia, with the increased adoption of more Western-style diets, according to a 2009 study conducted by Queen Elizabeth Hospital in Adelaide, Australia.

Although there may be hundreds of symptoms, the main ones are difficulty absorbing nutrients, oily diarrhoea, bloating and abdominal discomfort. Children with coeliac disease are often underweight, with vitamin deficiency and anaemia.

'You're going to have it for life. As traumatic as that is, it's a good disease to have, as diseases go,' says Erin Smith, 32, a New York-based blogger who has coeliac disease - diagnosed at the age of three - on glutenfreeglobetrotter.com. 'I don't need to take a treatment, pill or an injection - I can control my disease with food.'

Sometimes, however, this is easier said than done. When Voli had a sneaky taste of a scone at a friend's birthday party, she was laid low for days and vowed never to break her diet again.

But her experience was the impetus for her boyfriend, Ugo Foppa, and his business partner, Alexandre Tramontin, to introduce a line of gluten-free products to Hong Kong. Although such products are sold in select supermarkets around town, their taste and variety are less than desirable.

'Some of the gluten-free pasta is really lumpy and the aromas are not nice,' said Tramontin. So, he partnered with Piaceri Mediterranei, an Italian brand that offers a range of staples - pasta and bread substitutes, as well as cookies, cake mixes and baking flour.

'The main difference is they take out the wheat and other components that have gluten, say, the pasta,' says Tramontin. 'It's not rocket science but it is still tricky to get the same taste, texture and colour of [traditional] pasta.'

Gluten gives various doughs (think pizza, pasta, cake) their elasticity and volume. Without it, products will be crumbly, dense and dry. 'Products have definitely become much better than what I had growing up,' says Smith. 'As a kid, it was hard because you were ostracised for your weird food. Now, I can't even tell you how many breads there are in the market. And they taste like real bread, too.'

Those with coeliac disease were called 'banana babies' because it was thought to be a childhood disease and those diagnosed were put on a strict diet of bananas and rice. Historically, doctors have recommended diets consisting of pur?ed potatoes or tomatoes, beef steak, milk or just fruit.

Dining out is still a tricky proposition. Few local restaurants offer true gluten-free options. It may seem easy enough to choose foods that are not made from wheat - such as meat, vegetables, potatoes, or rice - but wheat gluten can sneak into the meal by way of additives, sauces, seasoning and bread. Even if you ask the waiting staff at a local restaurant, many may not be aware that even the ubiquitous soy sauce, for example, often contains wheat.

The consequences of such lapses might manifest themselves in different ways, including severe gastrointestinal distress, vomiting, abdominal discomfort, nausea, flatulence and/or fatigue. Or in coeliac speak, 'getting glutened'.

'The last time it happened, I felt like I was going to die. It's the worst feeling,' said Smith. Ironically, this incident happened at a gluten-free event that she was holding. The food was wrongly prepared and she had to leave halfway through dinner.

Eric Thompson, owner of food review site Gluten Free Globe (glutenfreeglobe.com), says it's easy to avoid 'getting glutened' in China, as long as you have a good translator. 'You have to ask that they make everything fresh for your order, to dust the chicken with potato or tapioca starch [rather than flour], and make sure they don't put soy sauce on anything.'

Given the trouble coeliacs have to go through, you'd think no one would go gluten-free by choice.

But Tramontin says the demand for gluten-free products is driven not only by coeliac disease, but also by a trend that began in the US. 'Although scientifically there is nothing to [support the claim], those who have gone on a gluten-free diet claim that it's a much lighter diet and there is a higher degree of digestibility,' he says.

Publicity of the disease has risen thanks to celebrities eschewing gluten of late - most notably, Serbian professional tennis player Novak Djokovic, who attributes his improved performance to the diet change. Oprah Winfrey, Jennifer Aniston, and Gwyneth Paltrow have also temporarily turned to gluten-free dieting for purported health benefits and weight loss.

Those who adopt a gluten-free diet often reduce the amount of fried and calorie-dense foods they eat, so they naturally shed weight.

But Smith says it's not a weight-loss tool. 'I tell people: I'm not losing weight because I'm still eating the same food that you are - mine just doesn't have any gluten in it.'