Keith Siau1, Linzie Priestnall1, Chris J J Mulder2, Sauid Ishaq3,4. 1. Department of Gastroenterology, Russell Hall Hospital, Dudley, UK. 2. Department of Gastroenterology, VU University Medical Centre, Amsterdam, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands. 3. Department of Gastroenterology, Russell Hall Hospital, Dudley, UK. sauid.ishaq@dgh.nhs.uk. 4. Department of Medicine, Birmingham City University, Birmingham, UK. sauid.ishaq@dgh.nhs.uk.