The charity Coeliac UK has called on the government to ensure all healthcare professionals implement new NICE guidelines on the assessment and treatment of the disease.
The guidance, published this week, identifies signs and symptoms - and conditions such as type 1 diabetes - which are linked to the disease.
If more people with these signs and symptoms were tested, it would drive up the diagnosis rate and help identify the half million people in the UK who are unaware they have the disease, the charity said.
Coeliac disease affects one in 100 people in the UK. However, research suggests that only one in eight of those affected have been diagnosed, leaving 500,000 people in the UK undiagnosed.
If left untreated, the disease can lead to infertility, multiple miscarriages, osteoporosis and bowel cancer.
Sarah Sleet, chief executive of Coeliac UK, said: ‘We are very pleased that NICE has published evidence-based guidelines, which must be taken up by medical practitioners to prevent years of misery for patients, and the needless waste of hard-pressed NHS resources.’