The aim of this study was to evaluate the incidence of colorectal neoplasia over time in patients with primary sclerosing cholangitis and inflammatory bowel disease (PSC-IBD) and to identify the risk factors associated with the development of colorectal dysplasia.

This retrospective study included 365 patients with PSC-IBD who were followed between 2007 and 2025, and underwent a total of 2,352 colonoscopies with high-definition white light endoscopy. Demographic and clinical data, endoscopic findings, and histological results were analyzed. Risk factors for dysplasia and carcinoma were assessed using a time-dependent Cox regression model. 

Dysplasia was detected in 76 patients (20.8%), with a neoplasia detection rate of 9.18%. A total of 216 dysplastic lesions were identified (50.9% from polypectomies and 49.1% from biopsies). Adenocarcinoma was diagnosed in 13 patients (3.6%). Statistically significant risk factors included higher age (HR = 1.03; P = 0.008), biologic therapy (HR = 2.48; P = 0.029), and disease duration (P < 0.001). The Mayo endoscopic subscore showed a positive trend toward significance (HR = 1.27; P = 0.051).

Our study confirms the high risk of colorectal neoplasia in patients with PSC-IBD, particularly in older individuals, those with longer disease duration, and those receiving biologic therapy. It highlights the importance of annual surveillance colonoscopies with both targeted and random biopsies.