Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2020; 26(28): 3998-4017
Published online Jul 28, 2020. doi: 10.3748/wjg.v26.i28.3998
Secondary causes of inflammatory bowel diseases
Yezaz A Ghouri, Veysel Tahan, Bo Shen
Yezaz A Ghouri, Veysel Tahan, Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Missouri- School of Medicine, Columbia, MO 65201, United States
Bo Shen, Department of Medicine and Surgery, Interventional IBD Center, Columbia University Irving Medical Center/New York Presbyterian Hospital, New York, NY 10032, United States
Author contributions: Ghouri YA review of scientific literature, writing of the manuscript and designing the table; Tahan V review of scientific literature and editing of the manuscript; Shen B review of scientific literature and editing of the manuscript.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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:
Corresponding author: Bo Shen, MD, Professor of the Edelman-Jarislowsky Surgical Sciences, Medicine and Surgical Sciences, Columbia University Irving Medical Center/New York Presbyterian Hospital, 161 Ft Washington Avenue, Herbert Irving Pavilion Rm 843, New York, NY 10032, United States.
Received: April 8, 2020
Peer-review started: April 8, 2020
First decision: April 30, 2020
Revised: May 15, 2020
Accepted: July 16, 2020
Article in press: July 16, 2020
Published online: July 28, 2020

Inflammatory bowel diseases (IBD), conventionally consist of Crohn’s disease (CD) and ulcerative colitis. They occur in individuals with high risk genotype for the disease in the setting of appropriate environmental factors. The pathogenesis of IBD involves a dysregulated autoimmune response to gut dysbiosis, which in turn is triggered due to exposure to various inciting environmental factors. But there is no clearly defined etiology of IBD and this type of disease is termed as “idiopathic IBD”, “classic IBD”, or “primary IBD”. We reviewed the current medical literature and found that certain etiological factors may be responsible for the development of IBD or IBD-like conditions, and we consider this form of de novo IBD as “secondary IBD”. Currently known factors that are potentially responsible for giving rise to secondary IBD are medications; bowel altering surgeries and transplantation of organs, stem cells or fecal microbiome. Medications associated with the development of secondary IBD include; immunomodulators, anti-tumor necrosis factor alpha agents, anti-interleukin agents, interferons, immune stimulating agents and checkpoint inhibitors. Colectomy can in some cases give rise to de novo CD, pouchitis of the ileal pouch, or postcolectomy enteritis syndrome. After solid organ transplantation or hematopoietic stem cell transplantation, the recipient may develop de novo IBD or IBD flare. Fecal microbiota transplantation has been widely used to treat patients suffering from recurrent Clostridium difficile infection but can also causes IBD flares.

Keywords: De novo inflammatory bowel disease, Secondary inflammatory bowel disease, Inflammatory bowel disease, Crohn’s disease, Ulcerative colitis

Core tip: Inflammatory bowel diseases (IBD) are chronic illnesses of the gastrointestinal tract with no clearly defined etiology and are traditionally termed as primary IBD. It is generally believed that IBD results from abnormal immune response to dysbiosis of gut microbiota in a genetically susceptible individual. IBD or IBD-like conditions may also be caused by well-defined etiologies; such as medical, surgical, and organ transplantation. These conditions are coined as secondary IBD. In this review we attempted to highlight some etiological factors, pathogenetic pathways, and clinical features of secondary IBD.