Introduction: To evaluate factors gastroenterologists consider most important to assess inflammatory bowel disease (IBD) severity in the real world. Methods: Full-time gastroenterologists practicing in the US for ≥1 year and affiliated with a community-based practice and/or academic center/hospital participated in a web-based survey. It consisted of multiple-choice questions where physicians ranked the top 5 factors they used to assess patients’ disease severity (eg, clinical indices [eg, CDAI, Mayo], GI symptoms). Factors ranked as most important and factors not ranked were summarized descriptively. Results were stratified by time spent managing patients with Crohn’s disease (CD) and ulcerative colitis (UC), workload, affiliation and number of IBD clinical trials participated in. Results: Two hundred physicians participated. Overall, presence of GI symptoms was most important to assess CD severity (37%), followed by ileocolonoscopy (25%), and quality of life (18%) (Table 1). Among the factors considered less important were clinical indices (e.g., CDAI) and fecal calprotectin, which were not ranked by 57% and 84% of physicians, respectively. For UC patients, GI symptoms (37.5%) and ileocolonoscopy (30%) were most important (Table 2). Clinical indices of UC activity (e.g., Mayo) and fecal calprotectin were not ranked by 67% and 82% of physicians, respectively. Physicians from community-based practices put more emphasis on laboratory tests (13%) than their counterparts in academic centers (2%) and those practicing in both settings (6%).Table 1: Importance of Factors Used to Assess CD SeverityTable 2: Factors Used to Assess UC SeverityConclusion: Tools used to assess severity of IBD patients are varied and most physicians do not rely on clinical indices or fecal calprotectin in routine practice. Lack of standardized instruments to evaluate disease severity in IBD patients may increase the risk of improper assessments of disease severity. Disclosure - T Ali: Speaker - AbbVie. Advisory Board - AbbVie, Janssen, Given Imaging, Luitpold Pharmaceuticals. AB Ozbay, S Wang, M Skup, R Thakkar, Jingdong Chao: Employee + Stockholder - AbbVie. B Gentile, D Cohen: Employee of ICON Plc, which received payment from AbbVie for conducting research analysis.