COVID-19 extrapulmonary illness - special gastrointestinal and hepatic considerations

Coronaviruses have caused three global outbreaks in the last 20 years, which include Severe Acute Respiratory Syndrome (SARS) caused by SARS-CoV (SARS-CoV-1), Middle East Respiratory Syndrome (MERS) by MERS-CoV and Coronavirus Disease-2019 (COVID-19) due to SARS-CoV-2. These outbreaks share many similarities, including clinical presentation, transmission, and management. Although respiratory manifestations are responsible for most of the morbidity and mortality in these conditions, extra-pulmonary manifestations such as gastrointestinal symptoms are also increasingly recognized as important symptoms. Important gastrointestinal symptoms include nausea, vomiting, anorexia, diarrhea, and abdominal pain. Hepatic manifestations such as abnormal aminotransferases are also noted in these patients. Early identification of GI symptoms is crucial as some patients can present only with GI manifestations in the absence of pulmonary symptoms. Furthermore, patients with diarrhea have tested positive for viral RNA in the stool. This has been reported even after the resolution of respiratory symptoms and can extend up to many days from the onset of symptoms. Because of this phenomenon, there is a theoretical risk of fecal-oral transmission and the potential spread of the disease. Though GI symptoms are frequently observed, understanding the pathogenesis of these symptoms is crucial, as it can not only of public health importance but could also identify infected patients early in the spread. Understanding the different GI and hepatic manifestations with underlying mechanisms of symptoms can assist in the therapeutic management of these patients. In this article, we summarize various GI and hepatic manifestations with their prevalence, underlying pathophysiology with emphasis on stool positivity.