ECCO-ESGAR Guideline for Diagnostic Assessment in IBD Part 1: Initial diagnosis, monitoring of known IBD, detection of complications. (23rd August 2018) - Maaser, Christian; Sturm, Andreas; Vavricka, Stephan R; Kucharzik, Torsten; Fiorino, Gionata; Annese, Vito; Calabrese, Emma; Baumgart, Daniel C; Bettenworth, Dominik; Borralho Nunes, Paula; Burisch, Johan; Castiglione, Fabiana; et al.