Observational Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 7, 2015; 21(1): 326-332
Published online Jan 7, 2015. doi: 10.3748/wjg.v21.i1.326
Impact of fecal occult blood on obscure gastrointestinal bleeding: Observational study
Yuka Kobayashi, Hirotsugu Watabe, Atsuo Yamada, Hirobumi Suzuki, Yoshihiro Hirata, Yutaka Yamaji, Haruhiko Yoshida, Kazuhiko Koike
Yuka Kobayashi, Hirotsugu Watabe, Atsuo Yamada, Hirobumi Suzuki, Yoshihiro Hirata, Yutaka Yamaji, Haruhiko Yoshida, Kazuhiko Koike, Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
Author contributions: Kobayashi Y, Watabe H, Yamada A, Yamaji Y and Koike K designed the research; Kobayashi Y, Watabe H, Yamada A and Suzuki H performed the research; Kobayashi Y, Watabe H, Yamada A, Hirata Y, Yamaji Y and Yoshida H analyzed the data; Kobayashi Y, Watabe H and Koike K wrote the paper.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Yuka Kobayashi, MD, PhD, Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. yukakobayashi-tky@umin.ac.jp
Telephone: +81-3-38155411 Fax: +81-3-38140021
Received: June 18, 2014
Peer-review started: June 19, 2014
First decision: July 21, 2014
Revised: August 8, 2014
Accepted: September 18, 2014
Article in press: September 19, 2014
Published online: January 7, 2015
Processing time: 202 Days and 19.6 Hours
Abstract

AIM: To elucidate the association between small bowel diseases (SBDs) and positive fecal occult blood test (FOBT) in patients with obscure gastrointestinal bleeding (OGIB).

METHODS: Between February 2008 and August 2013, 202 patients with OGIB who performed both capsule endoscopy (CE) and FOBT were enrolled (mean age; 63.6 ± 14.0 years, 118 males, 96 previous overt bleeding, 106 with occult bleeding). All patients underwent immunochemical FOBTs twice prior to CE. Three experienced endoscopists independently reviewed CE videos. All reviews and consensus meeting were conducted without any information on FOBT results. The prevalence of SBDs was compared between patients with positive and negative FOBT.

RESULTS: CE revealed SBDs in 72 patients (36%). FOBT was positive in 100 patients (50%) and negative in 102 (50%). The prevalence of SBDs was significantly higher in patients with positive FOBT than those with negative FOBT (46% vs 25%, P = 0.002). In particular, among patients with occult OGIB, the prevalence of SBDs was higher in positive FOBT group than negative FOBT group (45% vs 18%, P = 0.002). On the other hand, among patients with previous overt OGIB, there was no significant difference in the prevalence of SBDs between positive and negative FOBT group (47% vs 33%, P = 0.18). In disease specific analysis among patients with occult OGIB, the prevalence of ulcer and tumor were higher in positive FOBT group than negative FOBT group. In multivariate analysis, only positive FOBT was a predictive factors of SBDs in patients with OGIB (OR = 2.5, 95%CI: 1.4-4.6, P = 0.003). Furthermore, the trend was evident among patients with occult OGIB who underwent FOBT on the same day or a day before CE. The prevalence of SBDs in positive vs negative FOBT group were 54% vs 13% in patients with occult OGIB who underwent FOBT on the same day or the day before CE (P = 0.001), while there was no significant difference between positive and negative FOBT group in those who underwent FOBT two or more days before CE (43% vs 25%, P = 0.20).

CONCLUSION: The present study suggests that positive FOBT may be useful for predicting SBDs in patients with occult OGIB. Positive FOBT indicates higher likelihood of ulcers or tumors in patients with occult OGIB. Undergoing CE within a day after FOBT achieved a higher diagnostic yield for patients with occult OGIB.

Keywords: Capsule endoscopy; Fecal occult blood test; Obscure gastrointestinal bleeding; Small bowel diseases; Timing

Core tip: We investigated the association between small bowel diseases (SBDs) and a positive fecal occult blood test (FOBT) in patients with obscure gastrointestinal bleeding (OGIB). Positive FOBT may be useful for predicting SBDs in patients with occult OGIB. Positive FOBT indicates higher likelihood of ulcers or tumors in patients with occult OGIB. Undergoing capsule endoscopy within a day after FOBT achieved a higher diagnostic yield for patients with occult OGIB.