BACKGROUND: Postoperative recurrence (POR) occurs in up to 70% of patients with Crohn's disease (CD). The Rutgeerts score (RS) system may overestimate the prevalence of "real" anastomotic recurrence. Hence, we aimed to compare the prevalence of anastomotic POR in CD and the presence of ulcers at anastomotic sites in patients with right-side resection for colonic cancer (CC). METHODS: We retrospectively selected CD and CC patients with right-side resection and anti-peristaltic stapled L-L anastomosis from 5 tertiary referral centers. All patients underwent endoscopy within 8 months of surgery. POR was scored according to the modified RS. We directly compared the prevalence of isolated anastomotic ulcers in CD (Rutgeerts i2A) and CC patients. RESULTS: We enrolled 221 CD patients and 72 CC subjects. POR was recorded in 127 CD patients (57%). Endoscopy detected anastomotic ulcers in two of the 72 CC patients (3%), one (1.4%) being early local recurrence. The presence of isolated ulcerations was significantly higher in CD patients compared to CC (19% vs 3%; p < 0.01;OR 6.3). CONCLUSIONS: The prevalence of anastomotic (presumed ischemic) ulcers in CC patients is very low, but if shifted into the POR of CD, this is not representative of a real diagnostic matter. Prospective, multicenter, and direct comparative studies are needed to confirm our results.