Clinical Features and Pathophysiological Mechanisms of COVID-19-associated Gastrointestinal Manifestations

AIM AND OBJECTIVE: According to the literature, gastrointestinal (GI) involvement may have a remarkable influence on the course of coronavirus disease-2019 (COVID-19). Our aim with this article is to appraise clinical characteristics and presumptive biological mechanisms of digestive tract involvement of COVID-19. BACKGROUND: In this review article, the English language literature was reviewed by using PubMed and MEDLINE databases, up to February 2021. REVIEW RESULTS: The patients with GI involvement are generally presented with diarrhea, nausea/vomiting, anorexia, abdominal pain, and rarely GI bleeding. However, frequencies of these manifestations are diverse in studies published so far, depending on the countries where the studies were conducted, characteristics of the study populations, and methodological differences. Several studies proved that this novel coronavirus gets into the enterocytes by attaching to angiotensin-converting enzyme 2 receptor. Some of them have shown a direct viral invasion and replication of the virus within enterocytes. Along with detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients’ fecal materials, all these results explicitly indicate that the virus has the capability to invade the GI system. These findings may represent a potential risk indicator for fecal–oral spread of the virus. Although pathophysiology of COVID-19 associated GI manifestations remains elusive, direct viral damage, dysfunction in renin–angiotensin–aldosterone system, effects of gut–lung axis, and GI tract microbiome dysbiosis have been proposed as culprit mechanisms of the GI symptoms and inflammatory response. CONCLUSION: The patients with COVID-19 can be presented with diverse clinical manifestations including the GI symptoms. Understanding the actual impact of the virus on the GI tract depends on uncovering the pathophysiology of COVID-19. CLINICAL SIGNIFICANCE: GI involvement of COVID-19 appears to be crucial not only for its clinical consequences but also for its impacts on public health and prevention. HOW TO CITE THIS ARTICLE: Aslan AT, Şimşek H. Clinical Features and Pathophysiological Mechanisms of COVID-19-associated Gastrointestinal Manifestations. Euroasian J Hepato-Gastroenterol 2021;11(2):81–86.