Select the highest Rutgeerts grade identified at the anastomosis to visualize the relapse risk profile.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Endoscopic assessment of the neo-terminal ileum 6–12 months after ileocolic resection for Crohn's disease
To predict the risk of clinical recurrence and future surgical requirement
To guide "Step-up" biological therapy in patients who appear clinically well but have early endoscopic recurrence
The 'Silent' Recurrence
Up to 75% of patients will have endoscopic recurrence at the anastomosis by 1 year, even if they have no symptoms. Endoscopic monitoring is mandatory for preventing clinical relapses.
Section 2
Formula & Logic
The i0–i4 Grade
01
i0: No lesions in the neo-terminal ileum.
02
i1: ≤ 5 aphthous lesions.
03
i2: > 5 aphthous lesions with normal mucosa between lesions OR larger lesions limited to the anastomosis.
04
i3: Diffuse aphthous ileitis with inflamed mucosa.
05
i4: Diffuse inflammation with larger ulcers, nodules, and/or narrowing (stricture).
Recurrence Risk (at 10 years)
i0–i1
Low Risk (~5–10% symptomatic recurrence)
i2
Intermediate Risk (~40% recurrence)
i3–i4
High Risk (> 90% recurrence)
Section 3
Pearls/Pitfalls
The i2 Subdivision
Some experts subdivide i2 into: i2a (lesions limited to the anastomosis) and i2b (aphthous lesions in the ileum). i2b appears to have a worse prognosis than i2a, often justifying immediate biological start.
Triggering Biologicals
The finding of i2 or greater is a universal trigger to "Step-up" or initiate prophylactic biological therapy (Infliximab/Adalimumab) to prevent progressive stricturing disease.
Clinical Pearls
Post-operative endoscopy should ideally be scheduled at 6 months post-surgery
Smoking is the #1 modifiable risk factor for high Rutgeerts scores; recurrence rates are significantly higher in active smokers
The anastomosis itself is a site of mechanical trauma; purely anastomotic ulcers (i2a) without ileal lesions are sometimes more benign
Section 4
Next Steps
Management Decisions
01
i0–i1: Continue current (less aggressive) strategy; repeat endoscopy in 1–2 years.
02
i2–i4: Start or Escalate anti-TNF or anti-integrin therapy to prevent clinical failure.
Complementary Tools
SES-CD (Activity Score)
Lémann Index (Damage Score)
Montreal Classification (Phenotype)
Section 5
Evidence Appraisal
The Foundational Score
Predictability of the postoperative course of Crohn's disease.
Rutgeerts P et al. • Gastroenterology. 1990;99(4):956-63. Establishing the canonical post-op predictive score.
Developed by Professor Paul Rutgeerts at the University Hospital Gasthuisberg, Leuven, Belgium. Rutgeerts was a giant in IBD research who pioneered the concept that mucosal appearances (endoscopy) should drive therapy independently of how the patient feels.
