COVID-19: Focus on the lungs but do not forget the gastrointestinal tract

The coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 was declared in the last weeks as global pandemic. Currently affecting more than 5 000 000 individuals worldwide, COVID-19 is most commonly associated with symptoms caused by the acute respiratory distress syndrome (ARDS). As the number of infected individuals increases, we are learning that not only lungs, but also other organs can be affected by the virus. The gastrointestinal symptoms, for example diarrhoea, vomiting, nausea or abdominal pain, are frequent in patients with COVID-19. Moreover, alimentary tract symptoms may precede the respiratory presentation of SARS-CoV-2 infection. This can lead to delayed diagnosis and inappropriate management of infected patients. In addition, SARS-CoV-2 nucleic acid can be detected in faeces of infected patients and rectal swabs are even reported to remain positive for a longer period of time than nasopharyngeal swabs. Here, we aim to provide an update on the gastrointestinal involvement of COVID-19 presenting the symptoms that can be encountered in infected patients. We address the role of angiotensin-converting enzyme 2 (ACE2), as a functional receptor for SARS-CoV-2, which also was found in the gastrointestinal tract. Finally, we briefly discuss faecal shedding of SARS-CoV-2 and its potential role in the pathogenesis of the disease.