Background: Colonoscopy may be indicated in patients with coeliac disease who present with iron deficiency anaemia or in coeliac disease patients who have persisting diarrhoea despite being on a gluten-free diet. However, there are limited data to support this approach.
Methods: We prospectively recruited patients who were found to have coeliac disease, having been referred with newly diagnosed iron deficiency anaemia. We also recruited a second group of patients with known coeliac disease. These patients had persisting diarrhoea despite being on a gluten-free diet for 6 months. All patients had colonoscopy and were matched with controls (without coeliac disease) who had similar indications for colonoscopy.
Results: Ninety-eight consecutive new patients with coeliac disease and concurrent iron deficiency anaemia had colonoscopy performed. Twelve (12.2%) had pathology, three of which were carcinomas. This diagnostic yield was not significantly different from the findings in the control group 62/362 (17.1%) P=0.24. In coeliac disease patients with persisting diarrhoea (n=37), the diagnostic yield at colonoscopy was 1/37 (2.7%). This was significantly lower than our findings in the control group with chronic diarrhoea 55/390 (14%) P=0.05.
Conclusion: Colonoscopy should be considered in patients with coeliac disease (over the age of 45 years) who present with iron deficiency anaemia. Whilst, for coeliac disease patients with persisting diarrhoea (on a gluten-free diet) in the absence of sinister symptoms, a flexible sigmoidoscopy may be the initial investigation in order to exclude microscopic colitis. However, further larger prospective studies are required to evaluate this approach.