Gastrointestinal (GI) Tract
The pathogenesis of GI manifestations of COVID-19 is unknown and is likely multifactorial. Several mechanisms have been proposed, including the direct ACE 2-mediated viral cytotoxicity of the intestinal mucosa, cytokine-induced inflammation, gut dysbiosis, and vascular abnormalities.21,22
There is evidence that SARS-CoV-2 may be present in the gastrointestinal tract and that the angiotensin-converting enzyme 2 (ACE2) receptor is highly expressed throughout the gastrointestinal tract. Thus, SARS-CoV-2 may enter gastrointestinal cells via ACE2 receptors to cause direct damage to the gastrointestinal organs (Kaafarani, 2021).
Moreover, different studies have investigated that SARS-CoV-2 has been observed in the colonic tissues and feces of patients with COVID-19. 23
Acute cholecystitis has been widely reported in patients with COVID-19, especially those who are critically ill. In most patients, cholecystitis is acalculous, and the etiology remains largely unclear.
Acute pancreatitis has also been widely reported in patients with COVID-19, especially those with critical illness. However, the association between COVID-19 and acute pancreatitis is still poorly understood. 24
Loss of appetite was the most common gastrointestinal sequela. 28 out of 117 patients (24%) reported this symptom at 90 days. Other gastrointestinal sequelae included nausea (21 [18%]), acid reflux (21 [18%]), diarrhea (17 [15%]), abdominal distension (16 [14%]), belching (12 [10%]), vomiting (11 [9%]), abdominal pain (8 [7%]), and bloody stools (2 [2%]).COVID-19 can cause unusual gastrointestinal symptoms and impose some long-term symptoms, including loss of appetite, nausea, acid reflux, and diarrhea. These symptoms are common in patients 3 months after discharge from hospitalization due to COVID-19. Patients with severe COVID-19 can develop gastrointestinal complications, such as acute cholecystitis and acute pancreatitis.
Hepatobiliary Tract
The pathogenesis of liver injury in COVID-19 patients is unknown. Liver injury is likely multifactorial and may be explained by various hypotheses, including ACE-2-mediated viral replication in the liver and its resulting cytotoxicity, hypoxic or ischemic damage, immune-mediated inflammatory response, and drug-induced liver injury (DILI), or worsening of pre-existing liver disease.
21.Nazario, B. (2020, April 17). Digestive Symptoms of Coronavirus (COVID-19). WebMD. https://www.webmd.com/lung/covid19-digestive-symptoms#1.22. SystemScholar: Covid Long Haulers: Gastrointestinal https://www.harvard.edu.23. Weng, J., Li, Y., Li, J., Shen, L., Zhu, L., Liang, Y., Lin, X., Jiao, N., Cheng, S., Huang, Y., Zou, Y., Yan, G., Zhu, R., & Lan, P. (2021, May). Gastrointestinal sequelae 90 days after discharge for COVID-19. The Lancet. Gastroenterology & Hepatology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943402/#bib3.24. Kaafarani, H. M., et al. "Gastrointestinal Complications in Critically Ill Patients With COVID-19." Ann Surg. 2020 Aug;272(2):e61-e62. doi: 10.1097/SLA.0000000000004004. PMID: 32675498; PMCID: PMC7268843.
