Pasta can also elicit symptoms

Researchers conducted a survey of 1,000 people in central England.

It was found that 30 patients had coeliac disease. The average age of sufferers was 44 years, and many had experienced symptoms for months or even years without being diagnosed.

Out of the 30 patients, 25 suffered from anaemia of varying severity, but only five had the gastrointestinal symptoms traditionally associated with coeliac disease, such as diarrhoea, weight loss and bloating.

The findings reflect an earlier study of elderly sufferers in which almost half had visited their doctor for an average of 28 years with unexplained symptoms or blood test abnormalities.

The researchers, writing in the British Medical Journal, conclude that GPs should consider testing patients who complain of tiredness or who have unexplained anaemia for coeliac disease.

This can be done using a highly reliable antibody blood test.

It is officially estimated that one person in 1,000 suffers from coeliac disease.

However, the researchers estimate that if tests were carried out routinely a GP practice of 6,000 patients would identify on average 31.6 cases of the disease.

One of the study authors, Dr Harold Hin, a GP in Banbury, Oxfordshire, said: "Coeliac disease is intrinsically a gut disorder and one would expect to find abdominal problems.

"But nowadays more people who have coeliac disease present with other symptoms, such as anaemia.

"Most GPs still have the wrong impression that a patient has the condition then they must have gastrointestinal symptoms."