Stephan R. Vavricka

This paper is the first in a series of two publications relating to the European Crohn's and Colitis Organisation [ECCO] evidence-based consensus on the diagnosis and management of Crohn's disease and concerns the methodology of the consensus process, and the classification, diagnosis and medical management of active and quiescent Crohn's disease. Surgical management as well as special situations including management of perianal Crohn's disease of this ECCO Consensus are covered in a subsequent second paper [Gionchetti et al JCC 2016].

This new diagnostic consensus guideline is a joint project of the European Crohn’s and Colitis Organisation [ECCO] and the European Society of Gastrointestinal and Abdominal Radiology [ESGAR] that now merges the former ECCO-ESGAR Imaging Guideline and the former ECCO Endoscopy Guideline, also including laboratory parameters. It has been drafted by 30 ECCO and ESGAR members from 17 European countries. All the authors recognize th e work of and are grateful to previous ECCO and ESGAR members who contributed tocreating the earlier consensus guidelines on imaging and endoscopy. The former guidelines have been condensed into this new diagnostic consensus guideline which consists of two papers: the first detailing assessment at initial diagnosis, to monitor treat ment and for the detection of complications; the second dealing with the available scoring systems and general considerations regarding the different diagnostic tools. The strategy to define consensus was similar to that previously described in other ECCO consensus guidelines [available at www.ecco-ibd.eu]. Briefly, an open call for participants was made, with ECCO participants selected by the Guidelines’ Committee of ECCO [known as GuiCom] on the basis of their publication record and a personal statement and ESGAR participants nominated by ESGAR. The following working parties were established: diagnostics at initial diagnosis, diagnostics for monitoring treatment in patients with known IBD, diagnostics for the detect ion of complications, scores for IBD, and general principles and technical aspects. Provisional guideline statements and supporting text were written following a comprehensive literature review, then refined following two voting rounds. The first voting round introduced a more comprehensive voting procedure, in which each Guidelines participants voted on all statements by explicitly reviewing those statements together with their respective supporting text and references. The second voting round included optional national representative participation of ECCO’s 36 member countries and ESGAR’s 28 member countries. The level of evidence was graded according to the Oxford Centre for Evidence-Based Medicine [www.cebm.net]. The ECCO statements were finalized by the authors at a face-to-face meeting in Barcelona in October 2017 and represent consensus with agreement of at least 80% of the present participants. Consensus statements are intended to be read in context with their qualifying comments and not in isolation. The supporting text was then finalised under the direction of each working group leader [SV, TK, GF, VA, EC], before being integrated by the consensus leaders [CM, JS, AS].

Crohn’s disease [CD] is a chronic inflammatory bowel disease [IBD] that can result in progressive bowel damage and disability1. CD can affect individuals of any age, from children to the elderly, 2, 3 and may cause significant morbidity and impact on quality of life. Up to one-third of patients present with complicated behaviour [strictures, fistula, or abscesses] at diagnosis4. Most patients over time will develop a complication, with roughly 50% of patients requiring surgery within 10 years of diagnosis5-7. As the precise aetiology of CD remains unknown, a curative therapy is not yet available8. Several agents are available for the medical treatment of CD. Medical agents include mesalazine [5-ASA], locally active steroids [such as budesonide], systemic steroids, thiopurines such as azathioprine [AZA] and mercaptopurine [MP], methotrexate [MTX], and biological therapies [such as anti-TNF, anti-integrins, and anti-IL12/23]. \nThe European Crohn’s and Colitis Organisation [ECCO] produces and regularly updates several guidelines aimed at providing evidence-based guidance on critical aspects of IBD care to all healthcare professionals who manage patients with IBD. To provide high-quality evidence-based recommendations on medical and surgical treatment in CD, ECCO decided to develop these guidelines by adopting the GRADE [Grading of Recommendations Assessment, Development, and Evaluation] approach9. GRADE is a systematic process for developing guidelines that addresses how to frame the healthcare questions, summarize the evidence, ..

This article is the second in a series of two publications relating to the European Crohn's and Colitis Organisation [ECCO] evidence-based consensus on the management of Crohn's disease. The first article covers medical management; the present article addresses surgical management, including preoperative aspects and drug management before surgery. It also provides technical advice for a variety of common clinical situations. Both articles together represent the evidence-based recommendations of the ECCO for Crohn's disease and an update of previous guidelines.