UK based organizations have reported that people with celiac disease are waiting an average of 13 years to be diagnosed.
It is a gut disorder caused by gluten intolerance, and can lead to bone problems, infertility or bowel cancer.
Gluten is a protein group found in wheat and other flours that forms the structure of the bread dough. Gluten holds the carbon dioxide (CO2) produced by the yeast and expands during fermentation, and provides the elasticity and extensibility (stretch) in bread dough. Glutenin and gliadin are the two proteins that form gluten.
Gluten is generally found in rice, wheat and barley.
The only treatment for the condition is a life-long gluten-free diet.
The charity Celiac UK says some of the 800 patients surveyed in a recent poll reported seeing their general physician almost 30 times before being diagnosed.
But it says the condition can be easily detected by GPs using a quick and simple blood test.
People with celiac disease can experience a range of symptoms, including bloating, diarrhea, chronic fatigue, breathlessness, depression and weight gain.
Children with the condition can have behavioral, learning or concentration problems.
Norma Mc Gough, head of diet at Celiac UK, said the delays in diagnosis were a combination of patients not recognizing, or getting used to, their symptoms - or that doctors were not considering celiac disease as an explanation for what could be a vague range of symptoms.
Celiac UK chief executive Sarah Sleet said: "Celiac disease is considered to be the most under-diagnosed common chronic condition in the UK today.
"One in 100 are believed to be at risk from the condition, but the latest research suggests only one in eight, or 12.5%, of these have been diagnosed.
"And yet, it is easy to diagnose with inexpensive blood tests available to quickly identify cases in primary care.
"There is no reason why people should not be diagnosed more quickly, and avoid years of debilitating pain and ill-health."
Professor Mayur Lakhani, head of the Royal College of GPs said: "Awareness of celiac disease is increasing but doctors do find it a difficult condition to consider for diagnosis as its symptoms are also mimicked by many other common disorders.
"However, more needs to be done and can be done. I would urge all doctors to be more vigilant about this condition and to request the simple blood test which can clinch an early diagnosis."