Endoscopic-radiological correlation in idiopathic inflammatory bowel disease : comparison of colonoscopy and double contrast barium enema in 99 patients with previously well-established Crohn's disease of the colon and ulcerative colitis / Johannes DijkstraColonoscopic polypectomy : a detailed analysis of 1930 polypectomies performed during 3500 colonoscopies / Koen Gie TanColonoscopic polypectomy : a detailed analysis of 1930 polypectomies performed during 3500 colonoscopies / Koen Gie Tan