Table 1.

Factors contributing to overall disease severity in patients with IBD, use to identify patients at high risk of disease-related complications including surgery, hospitalization and disability.

	High-risk Crohn’s disease	Low-risk Crohn’s disease
Structural Damage	• Large or deep mucosal lesions • Fistula and/or perianal abscess • Prior intestinal resections, particularly of segments >40cm • Presence of strictures	• Aphthous or small superficial ulcers • Absence of fistulae, abscess or strictures • No prior intestinal surgeries
Inflammatory burden	• Extensive disease (ileal involvement >40cm or pancolitis) • Elevated C-reactive protein • Low albumin	• Limited anatomic involvement • Normal C-reactive protein • Normal albumin
Impact on quality of life	• Presence of stoma • >10 loose stools/week • Lack of symptomatic improvement with prior exposure to biologics and/or immunosuppressive agents • Significant impact of disease on activities of daily living • Presence of anorectal symptoms (anorectal pain, bowel urgency, incontinence, discharge, tenesmus) • Anemia • Daily abdominal pain • Corticosteroid use within last 1 year	• Modest impact of disease on daily activities • No prior exposure to biologics and/or immunosuppressive agents • No prior disease-related hospitalization within the last 1 year • Absent to mildly active symptoms
Emerging predictors	• High number and titer of anti-microbial antibodies • Antimicrobial genetic peptide signature	-