Epidemiology of obscure gastrointestinal bleeding in China: A single-center series and comprehensive analysis of literature

OBJECTIVETo determine the etiologies of obscure gastrointestinal bleeding (OGIB) in a Chinese population using a retrospective case series and a systematic analysis of the literatures on OGIB in Chinese patients. METHODSA large enteroscopy database in a tertiary endoscopic center was searched to identify patients with OGIB from 2010 to 2016. The patients' characteristics and diagnostic findings were collected and analyzed. A comprehensive search of the literature was carried out to harvest all relevant studies published from 2004 to 2016. RESULTSIn total, 708 patients were included in the case series. The most common causes of OGIB were inflammatory diseases (36.3%), non-small bowel lesions (10.2%) and neoplasms (10.0%). A systematic analysis of the literatures included 39 studies providing relevant data for 3145 patients with a pooled detection rate of 84.2%. Inflammatory lesions (27.4%), neoplasms (18.5%), vascular lesions (16.1%) and diverticula or intestinal duplication (11.9%) were the most common causes of OGIB. CONCLUSIONSInflammatory lesions, neoplasms, vascular lesions and diverticula or intestinal duplication are the most common in Chinese OGIB patients, while in pediatric patients diverticula or intestinal duplication, vascular lesions and Crohn's disease are prevalent. Furthermore, the etiologies of OGIB distribute differently across different areas in China.