Gastrointestinal manifestations in COVID-19

Coronavirus disease 2019 (COVID-19), a respiratory viral infection, has affected more than 78 million individuals worldwide as of the end of December 2020. Previous studies reported that severe acute respiratory syndrome coronavirus 1 and Middle East respiratory syndrome-related coronavirus infections may affect the gastrointestinal (GI) system. In this review we outline the important GI manifestations of COVID-19 and discuss the possible underlying pathophysiological mechanisms and their diagnosis and management. GI manifestations are reported in 11.4-61.1% of individuals with COVID-19, with variable onset and severity. The majority of COVID-19-associated GI symptoms are mild and self-limiting and include anorexia, diarrhoea, nausea, vomiting and abdominal pain/discomfort. A minority of patients present with an acute abdomen with aetiologies such as acute pancreatitis, acute appendicitis, intestinal obstruction, bowel ischaemia, haemoperitoneum or abdominal compartment syndrome. Severe acute respiratory syndrome coronavirus 2 RNA has been found in biopsies from all parts of the alimentary canal. Involvement of the GI tract may be due to direct viral injury and/or an inflammatory immune response and may lead to malabsorption, an imbalance in intestinal secretions and gut mucosal integrity and activation of the enteric nervous system. Supportive and symptomatic care is the mainstay of therapy. However, a minority may require surgical or endoscopic treatment for acute abdomen and GI bleeding.