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World J Gastroenterol. Jul 28, 2021; 27(28): 4504-4535
Published online Jul 28, 2021. doi: 10.3748/wjg.v27.i28.4504
Gastrointestinal and hepatic diseases during the COVID-19 pandemic: Manifestations, mechanism and management
Dina Zakaria Mohamed, Mai El-Sayed Ghoneim, Sally El-Sayed Abu-Risha, Ramy Ahmed Abdelsalam, Mohamed Abdelhalem Farag
Dina Zakaria Mohamed, Sally El-Sayed Abu-Risha, Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tanta University, Tanta 31511, Egypt
Mai El-Sayed Ghoneim, Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Sadat City, Menoufia 32632, Egypt
Ramy Ahmed Abdelsalam, Department of Pathology, Faculty of Medicine, Mansoura University, Mansoura 35511, Egypt
Mohamed Abdelhalem Farag, Department of Pediatrics, Nebru General Hospital, Nebru 35511, Egypt
Author contributions: All authors contributed equally to the conception and topics for this review and to revising the article critically for intellectual content; all authors approved the final version of the manuscript for submission.
Conflict-of-interest statement: The authors have no conflicts of interest to declare. The authors only are responsible for the content and writing of the 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: Dina Zakaria Mohamed, MSc, Assistant Lecturer, Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tanta University, El-Geish Street, Tanta 31511, Egypt.
Received: January 15, 2021
Peer-review started: January 15, 2021
First decision: January 31, 2021
Revised: February 12, 2021
Accepted: June 7, 2021
Article in press: June 7, 2021
Published online: July 28, 2021
Processing time: 191 Days and 17.6 Hours

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered the causative pathogen of coronavirus disease 2019 (COVID-19) and has become an international danger to human health. Although respiratory transmission and symptoms are still the essential manifestations of COVID-19, the digestive system could be an unconventional or supplementary route for COVID-19 to be transmitted and manifested, most likely due to the presence of angiotensin-converting enzyme 2 (ACE2) in the gastrointestinal tract. In addition, SARS-CoV-2 can trigger hepatic injury via direct binding to the ACE2 receptor in cholangiocytes, antibody-dependent enhancement of infection, systemic inflammatory response syndrome, inflammatory cytokine storms, ischemia/reperfusion injury, and adverse events of treatment drugs. Gastrointestinal symptoms, including anorexia, nausea, vomiting, and diarrhea, which are unusual in patients with COVID-19, and some digestive signs may occur without other respiratory symptoms. Furthermore, SARS-CoV-2 can be found in infected patients’ stool, demonstrating the likelihood of transmission through the fecal-oral route. In addition, liver function should be monitored during COVID-19, particularly in more severe cases. This review summarizes the evidence for extra-pulmonary manifestations, mechanisms, and management of COVID-19, particularly those related to the gastrointestinal tract and liver.

Keywords: COVID-19, Angiotensin-converting enzyme 2, Gastrointestinal, Inflammatory bowel disease, Liver, Management

Core Tip: The coronavirus disease 2019 (COVID-19) pandemic has affected millions worldwide, with high lethality. In addition to typical respiratory symptoms of COVID-19, gastrointestinal and hepatic symptoms have been frequently observed in COVID-19 patients. The main purpose of this article is to focus on the manifestations, mechanisms, and management of the gastrointestinal tract and liver that occurred during the course of COVID-19. Therefore, physicians must not undervalue the digestive symptoms during COVID-19 and rapidly adjust the treatment options for COVID-19 patients with gastrointestinal symptoms and liver enzyme abnormalities.