We read with interest the study by van der Wouden et al (Gut 2007;56:444–5). The authors describe their experience of investigating patients with irritable bowel syndrome (IBS fulfilling the Rome II criteria) for coeliac disease. They tested 152 patients with IBS using IgA endomysial antibodies and total IgA level or duodenal biopsy; 36 patients were subsequently biopsied but there were no cases of coeliac disease diagnosed (prevalence 0%: 95% confidence interval, 0% to 4%). They concluded that the prevalence of coeliac disease in patients with IBS is low and that screening may be ineffective.

We feel cautious about accepting these results as definitive proof of no relation between these two common conditions. Their study has some methodological limitations. First, the …