1. Department of Internal Medicine, Zaans Medisch Centrum, 210 1500 EE Zaandam, The Netherlands
2. Department of Gastroenterology, Zaans Medisch Centrum, 210 1500 EE Zaandam, The Netherlands
3. Department of Pathology, Zaans Medisch Centrum, 210 1500 EE Zaandam, The Netherlands