['Coeliac disease (CD) is one of the most important causes of chronic diarrhoea. The prevalence of CD in patients with chronic diarrhoea in Iran remains unknown. The aim of this study was to evaluate the prevalence of CD among 100 Iranian patients with chronic non-bloody diarrhoea.', 'One hundred consecutive patients with chronic non-bloody diarrhoea of more than 6 weeks attending an academic centre in Iran were enrolled. Patients with bloody diarrhoea and renal failure were excluded. IgA endomysial antibody (IgA EMA), IgA antigliadin antibody (IgA AGA), and total serum IgA were tested in all patients. Patients with negative IgA EMA were evaluated for other causes of chronic diarrhoea. Patients who had positive IgA EMA underwent upper gastrointestinal endoscopy and duodenal biopsy. Patients with a positive IgA EMA were advised to follow a gluten-free diet (GFD) strictly for 6 months, and then clinical symptoms, serological and haematological tests were re-assessed.', "A total of 100 patients (55 men and 45 women) with chronic non-bloody diarrhoea were studied. Mean age of the patients was 31 years. Total serum IgA was in the normal range in all participants. Twenty patients (12/45 women; 8/55 men) had positive IgA EMA. Fourteen of them also had a positive IgA AGA. CD was diagnosed in 19 patients (19%). Small intestinal Crohn's disease, small intestinal lymphoma and idiopathic aetiology were the next. In patients with CD, after 6 months of a GFD, 15 patients (75%) had a complete clinical response, three patients (15%) had a good response, and one patient (5%) had a partial response. One patient did not follow a GFD."] Is coeliac disease the most common cause of chronic diarrhoea in Iran?