P183 The prevalence of incidental terminal ileitis in persons undergoing non-diagnostic colonoscopy: a meta-analysis

Abstract

Abstract Background Incidentally diagnosed terminal ileitis has been reported among asymptomatic persons undergoing non-diagnostic colonoscopy. The purpose of our study was to determine the prevalence and long-term outcomes of asymptomatic terminal ileitis. Methods We developed and executed a systematic search strategy in three biomedical databases (Medline, Embase and Web of Science) and relevant scientific meeting abstracts, from inception to May 1, 2019, to identify observational studies that reported the prevalence of asymptomatic terminal ileitis in adults undergoing screening or polyp surveillance colonoscopy, and/or the long-term outcomes of such lesions. A random-effects meta-analysis was conducted to determine the pooled prevalence rate, confidence interval (CI), and report the heterogeneity score I2. Risk factors for progression to overt CD were abstracted. Results Of 2388 eligible studies, 1784 were screened after excluding duplicates, 84 were reviewed in full text and 14 studies were eligible for inclusion. Eight studies reported the prevalence of asymptomatic terminal ileitis in 46,460 persons undergoing non-diagnostic colonoscopy, and eight (two of eight reporting prevalence) studies reported follow-up data. The pooled rate of asymptomatic terminal ileitis was 1.5% (CI 1.0%, 16.3%), with I2 of 0 (Figure). The use of non-steroidal anti-inflammatory drugs varied between 0% and 37%. Of 147 persons with asymptomatic terminal ileitis with follow-up data (range 13–63.6 months in three studies), five had progression to CD, three were treated for CD with steroids, 5-amino salicylates, azathioprine and vedolizumab, and lesions resolved in four. Three studies reported the absence of symptoms as a predictor of lack of progression. Conclusion Asymptomatic terminal ileitis can be found incidentally in 1.5% of non-diagnostic colonoscopies. Based on limited data, the rate of its progression to overt CD seems low, and watchful waiting could likely be a reasonable strategy. More long-term follow-up studies are needed to inform the natural history of incidental terminal ileitis, factors that predict progression to CD and therapeutic implications.