Gastrointestinal symptoms and disorders related to COVID-19. Lessons learned from gastroenterologists

COVID-19 is mainly a respiratory illness caused by the SARS-CoV-2 but can also lead to GI symptoms. The primary host receptor which mediates the mechanism as SARS-CoV-2 enters the cell is the ACE2 receptor. Therefore, GI symptoms can be common in COVID-19, and in some cases, they are the first manifestation even before fever and respiratory symptoms. In addition, the liver function tests alteration often is related to a worse prognosis. The exact incidence of GI symptoms is a matter of debate. Moreover, wide variation concerning GI symptoms frequency exists, but the predominant ones seem to be diarrhea, anorexia, nausea, vomiting, and abdominal pain or discomfort. This review summarizes the most relevant findings of COVID-19 on the digestive system, including the liver, biliary tract, pancreas, the most common GI symptoms, and the atypical clinical GI manifestations