Prevalence And Characteristics Of Incidentally Diagnosed Inflammatory Bowel Disease During Screening Colonoscopy

Abstract Background Colonoscopy is the most powerful tool for colon cancer screening. As the performance rate of screening colonoscopy was rapidly increased, there was also a great increase in the incidental detection of inflammatory lesions during screening colonoscopy. The significance and clinical course of these lesions were never been investigated. The aim of this study is to evaluate the prevalence and clinical significance of incidentally detected inflammatory lesions during screening colonoscopy and investigate the characteristics of newly diagnosed inflammatory bowel disease among them. Methods Health check-up patients who underwent screening colonoscopy at Seoul National University Hospital Healthcare System Gangnam Center in 2018 were enrolled. Among them, patients who showed endoscopic inflammatory lesions such as ulcer, erosion, erythema, spontaneous bleeding, friability or exudate were selected. We reviewed the pathologic reports of those patients. We investigated if there were suggestive pathologic findings of inflammatory bowel disease, which were defined as presence of one of these findings: cryptitis, crypt abscess, crypt distortion, crypt atrophy or noncaseating granuloma. We classified them as possible inflammatory bowel disease patients and closely monitored clinical course of these patients. We investigated prevalence of incidentally diagnosed inflammatory bowel disease among health check-up patients. Results A total of 10366 patients underwent screening colonoscopy at Seoul National University Hospital Healthcare System Gangnam Center. Among them, 237 patients showed inflammatory lesions on colonoscopy. Nine patients were already diagnosed with inflammatory bowel disease; 1 with Bechet’s disease and 8 with ulcerative colitis. The others had no previous medical history of colonic disease. Biopsy specimens were obtained in 200 patients. Eighteen patients showed one of suggestive pathologic findings of inflammatory bowel disease. Among them, 12 patients did not undergo further diagnostic examination because they did have no associated symptom. Two patients immediately diagnosed as ulcerative colitis and other 4 patients underwent short-term follow-up colonoscopy. Three of them showed resolution of previously noted inflammatory lesions and the remaining one finally diagnosed with ulcerative colitis. Briefly, 3 patients were diagnosed with inflammatory bowel disease, 3 with eosinophilic colitis, 1 with tuberculosis, and 1 with amoebic colitis. Conclusion Incidental detection of inflammatory lesions during screening colonoscopy was relatively high; however, prevalence of inflammatory bowel disease is low. Careful examination of associated symptom and sustained close long-term follow-up are needed.