Review
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 14, 2017; 23(26): 4689-4700
Published online Jul 14, 2017. doi: 10.3748/wjg.v23.i26.4689
Diarrhea after bariatric procedures: Diagnosis and therapy
Yves M Borbély, Alice Osterwalder, Dino Kröll, Philipp C Nett, Roman A Inglin
Yves M Borbély, Alice Osterwalder, Dino Kröll, Philipp C Nett, Roman A Inglin, Clinic for Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, 3004 Bern, Switzerland
Author contributions: All authors equally contributed to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and final approval of the final version.
Conflict-of-interest statement: Authors declare no conflict of interest for this article.
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: Roman A Inglin, MD, Clinic for Visceral Surgery and Medicine, Inselspital, Bern University Hospital, University of Bern, Tiefenau Site, Tiefenaustrasse 112, 3004 Bern, Switzerland. roman.inglin@insel.ch
Telephone: +41-31-3088855 Fax: +41-31-3088812
Received: December 29, 2016
Peer-review started: December 30, 2016
First decision: March 16, 2017
Revised: March 30, 2017
Accepted: June 18, 2017
Article in press: June 19, 2017
Published online: July 14, 2017
Processing time: 195 Days and 1.3 Hours
Abstract

Diarrhea after bariatric procedures, mainly those with malabsorptive elements including Roux-Y Gastric Bypass and Biliopancreatic Diversion, is common and an essential determinant of quality of life and micro- and macronutrient deficiencies. Bariatric surgery is the only sustainably successful method to address morbid obesity and its comorbidities, particularly gaining more and more importance in the specific treatment of diabetic patients. Approximately half a million procedures are annually performed around the world, with numbers expected to rise drastically in the near future. A multitude of factors exert their influence on bowel habits; preoperative comorbidities and procedure-related aspects are intertwined with postoperative nutritional habits. Diagnosis may be challenging owing to the characteristics of post-bariatric surgery anatomy with hindered accessibility of excluded segments of the small bowel and restriction at the gastric level. Conventional testing measures, if available, generally yield low accuracy and are usually not validated in this specific population. Limited trials of empiric treatment are a practical alternative and oftentimes an indispensable part of the diagnostic process. This review provides an overview of causes for chronic post-bariatric surgery diarrhea and details the particularities of its diagnosis and treatment in this specific patient population. Topics of current interest such as the impact of gut microbiota and the influence of bile acids on morbid obesity and especially their role in diarrhea are highlighted in order to provide a better understanding of the specific problems and chances of future treatment in post-bariatric surgery patients.

Keywords: Bariatric surgery; Diarrhea; Malnutrition; Malabsorption; Steatorrhea; Dumping syndrome; Bile acids and salts; Gut microbiota; Blind loop syndrome

Core tip: Bariatric surgery is the only sustainable therapy for morbid obesity and its comorbidities. Postoperative diarrhea is common and an essential determinant of quality of life and micro- and macronutrient deficiencies. The distinctive anatomic changes after bariatric procedures with exclusion of various length of small bowel have a severe impact not only on diagnostic but also puts limits on therapeutic means. This review provides an overview of causes for chronic diarrhea in the particular context of post-bariatric patients, and details specific problems in diagnosis and treatment of this challenging patient population.