Coeliac disease is a lifelong intolerance to the gluten found in wheat, barley 
and rye, and some patients are also sensitive to oats. The disease is 
genetically determined, with 10% of the first-degree relatives affected and 75% 
of monozygotic twins being concordant. Of the patients with coeliac disease 95% 
are human leucocyte antigen (HLA)-DQ2 or HLA-DQ8 positive. Characteristically, 
the jejunal mucosa becomes damaged by a T-cell-mediated autoimmune response that 
is thought to be initiated by a 33-mer peptide fragment in A2 gliadin, and 
patients with this disorder have raised levels of anti-endomysium and tissue 
transglutaminase antibodies in their blood. Coeliac disease is the major 
diagnosable food intolerance and, with the advent of a simple blood test for 
case finding, prevalence rates are thought to be approximately 1:100. 
Classically, the condition presented with malabsorption and failure to thrive in 
infancy, but this picture has now been overtaken by the much more common 
presentation in adults, usually with non-specific symptoms such as tiredness and 
anaemia, disturbance in bowel habit or following low-impact bone fractures. 
Small intestinal biopsy is necessary for diagnosis and shows a 
characteristically flat appearance with crypt hypoplasia and infiltration of the 
epithelium with lymphocytes. Diet is the key to management and a gluten-free 
diet effectively cures the condition. However, this commitment is lifelong and 
many aisles in the supermarket are effectively closed to individuals with 
coeliac disease. Compliance can be monitored by measuring antibodies in blood, 
which revert to negative after 6-9 months. Patients with minor symptoms, who are 
found incidentally to have coeliac disease, often ask whether it is necessary to 
adhere to the diet. Current advice is that dietary adherence is necessary to 
avoid the long-term complications, which are, principally, osteoporosis and 
small bowel lymphoma. However, risk of these complications diminishes very 
considerably in patients who are on a gluten-free diet.