A Perth woman who was taken to hospital after eating a supposedly gluten-free meal wants restaurateurs to know coeliac disease is a life-threatening condition — not a trendy “fad”.

Kate Williams had dined with husband Scott at the same city restaurant previously but last week, after a dish of chicken with what she thought were gluten-free waffles, she was ill.

The 27-year-old drifted in and out of consciousness and had mild kidney failure.

The CrossFit fanatic, who was diagnosed as coeliac at 12 months of age, said she was lucky she was so fit.

“If I was already sick or if I was an elderly person and I had this sort of reaction, I could have died,” Ms Williams said.

The restaurant owner said she was investigating what went wrong on the morning of May 26.

“I’m trying to find out what happened because we’ve never had an issue with this,” she said.

“I was upset — I would never want to hurt anyone at all.”

It came after revelations last week that almost 10 per cent of food sold as gluten-free at cafes and restaurants across Melbourne contained gluten.

While the Perth restaurant’s menu had dishes available as gluten-free options, it also carried a disclaimer that they may contain traces of gluten.

The owner said the gluten-free options were for those who opted not to eat gluten.

“If you’re really coeliac or really gluten intolerant, we don’t recommend that you eat the gluten-free,” she said.

“We only have one kitchen and flour is obviously airborne, so there’s always the possibility of cross-contamination.”

Coeliac Australia’s Cathy Di Bella said restaurants could not temper a “gluten-free” claim with a “may contain traces of” disclaimer. She said gluten, which can cause serious illness in coeliacs, had become the “forgotten allergen”.

The organisation has set up gluten standards to help the hospitality industry and an accreditation program, which Ms Williams believes should be mandatory for those claiming to be gluten-free.

“If they’re not prepared to put in that effort and time to make sure that it’s gluten-free, then they shouldn’t advertise it as such,” Ms Williams said.

The restaurant has offered Ms Williams a $40 refund with a confidentiality clause, which she intends to decline so she can speak out and educate others about the risks of dining out.

“I have lost faith in going out for dinner and it’s going to take me a long time to be able to go out and do that without fear of this happening,” she said.