Epidemiology of obscure gastrointestinal bleeding in China:
A single-center series and comprehensive analysis of literature
Yao ZHANG ,*
Sui Yi WU,
Yi Qi DU ,* Bing Han LI,
Chen Fei LI,
Zhao Shen LI * & Yu BAI*
*Department of Gastroenterology, Changhai Hospital, Second Military Medical University, and
Basic Medicine, Second Military Medical University, Shanghai, China
OBJECTIVE: To determine the etiologies of obscure
gastrointestinal bleeding (OGIB) in a Chinese popula-
tion using a retrospective case series and a systematic
analysis of the literatures on OGIB in Chinese patients.
METHODS: A large enteroscopy database in a ter-
tiary 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 litera-
ture was carried out to harvest all relevant studies
published from 2004 to 2016.
RESULTS: In 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 sys-
tematic 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.
CONCLUSIONS: Inﬂammatory lesions, neoplasms,
vascular lesions and diverticula or intestinal duplica-
tion 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
KEY WORDS: China, double-balloon enteroscopy, etiology, obscure gastrointestinal hemorrhage, single-
Obscure gastrointestinal bleeding (OGIB) refers to
blood loss from unclear origins after esophagogastro-
duodenoscopy (EGD), colonoscopy or radiological
evaluation of the small bowel.
Patients may present
with overt bleeding, hematemesis, hematochezia or
melena, or complain of positive fecal occult blood.
Small intestinal bleeding or middle gastrointestinal
bleeding (MGIB) is deﬁned as the source of bleeding
that is located between the ligament of Treitz and the
It has been reported that MGIB
accounts for 80% of the OGIB.
Because of the length
and complexity of the small bowel, it is quite
Correspondence to: Zhao Shen LI, Department of Gastroenterology,
Changhai Hospital, Second Military Medical University,
No. 168 Changhai Road, Yangpu District, Shanghai 200433, China.
Email: firstname.lastname@example.org; or Yu BAI, Department of
Gastroenterology, Changhai Hsopital, Second Military Medical
University, No. 168 Changhai Road, Yangpu Dstrict, Shanghai 200433,
China. Email: email@example.com
Conﬂict of interest: None.
Accepted for publication 12 December 2017.
© 2017 Chinese Medical Association Shanghai Branch, Chinese
Society of Gastroenterology, Renji Hospital Afﬁliated to Shanghai
Jiaotong University School of Medicine and John Wiley & Sons
Journal of Digestive Diseases 2018; 19; 33–39 doi: 10.1111/1751-2980.12568