Chronic pouchitis is associated with pouch polyp formation in patients with underlying ulcerative colitis
Background: Polypoid lesions can develop in ileal pouches. The risk factors associated with the development of pouch polyps have not been studied. Aim: To characterize clinical features, risk factors, and disease course of pouch polyp in a cohort of patients with underlying inflammatory bowel disease (IBD) from a subspecialty clinic. Method: A total of 1094 patients with restorative proctocolectomy and IPAA for IBD presenting to our Pouchitis Clinic from 2002 to 2010 were included. Demographic, clinical, and endoscopic variables were analyzed. Results: The median durations from UC diagnosis to colectomy and from pouch creation to the last follow-up for the whole cohort were 6 (interquartile range [IQR]: 3-13) and 9. years (IQR: 5-14), respectively. A total of 2472 surveillance and/or diagnostic pouchoscopies were performed for the cohort with a median follow-up of 5 (IQR: 2-6) years in the Pouchitis Clinic. The median number of pouchoscopies per patient was 2 (IQR: 1-3). Of the 1094 patients, 96 (8.8%) were found to have pouch polyps. The median size of the polyps was 1.2 (IQR: 1.0-2.0) cm. On histology, 93 patients (96.9%) had inflammatory-type polyps and 3 (3.1%) had polyps with low-grade dysplasia or indefinite for dysplasia. Multivariate logistic regression analysis demonstrated that chronic pouch inflammatory change was a risk factor for the development of pouch polyp with an odds ratio of 2.26 (95% confidence interval: 1.35-3.79; P. = 0.002). Conclusion: The majority of pouch polyps in patients with underlying UC were benign. Patients with concomitant chronic pouch inflammatory changes had an increased risk for developing pouch polyps.