In the second century CE (AD), the Greek physician Aretaeus wrote a description of chronic diarrhoea with malabsorption, calling it διαθεσις κοιλιακος (“coeliac diathesis”), which simply means something going wrong in the abdomen. Samuel Gee revived the term in 1888 and gave a classic description of children with diarrhoea, bloating, and wasting of unknown origin. One hundred years later, the cause (gluten) and the definitive diagnostic test (villous atrophy on small intestinal biopsy) were well established, but the prevalence was still thought to be about 1 in 1000. Then along came easily performed antibody assays, first to gliadin, then to endomysium, and most recently to transglutaminase, and it soon became apparent that the true prevalence of autoimmune disease due to gluten is about 1 in a 100. The clinical features are mostly non-specific and non-abdominal: typically tiredness and recurrent anaemia. Detecting it depends on having a low threshold for ordering antibody tests. Now you can even do them on the spot, since an Italian study shows excellent correlation between standard anti-transglutaminase assays and rapid testing kits (