COVID-19 in gastroenterology and hepatology: Lessons learned and questions to be answered

Background Although coronavirus disease 2019 (COVID-19) presents primarily as a lower respiratory tract infection, increasing data suggests multiorgan, including the gastrointestinal (GI) tract and liver, involvement in patients who are infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Aim To provide a comprehensive overview of COVID-19 in gastroenterology and hepatology. Methods Relevant studies on COVID-19 related to the study aim were undertaken through a literature search to synthesize the extracted data. Results We found that digestive symptoms and liver injury are not uncommon in patients with COVID-19 and varies in different individuals. The most common GI symptoms reported are diarrhea, nausea, vomiting, and abdominal discomfort. Other atypical GI symptoms, such as loss of smell and taste and GI bleeding, have also been reported along with the evolvement of COVID-19. Liver chemistry abnormalities mainly include elevation of aspartate transferase, alanine transferase, and total bilirubin. It is postulated to be related to the binding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus to the angiotensin converting enzyme-2 receptor located on several different human cells. Conclusion Standardized criteria should be established for diagnosis and grading of the severity of GI symptoms in COVID-19 patients. Gastroenterology and hepatology in special populations, such as children and elderly, should be the focus of further research. Future long-term data regarding GI symptoms should not be overlooked.