How COVID-19 affects the Gastrointestinal System?

How COVID-19 affects the Gastrointestinal System?

Ever since the outbreak of Coronavirus reported from China back in December 2019, it has spread to rest of the world and became a global pandemic. Till date, the virus has infected over 67,152 people in India and resulted in 2,206 deaths. 

Any virus has the potential to destroy healthy cells and multiply itself. The new virus SARS-CoV-2 (COVID-19) mainly attacks the lining of the airways in the cells thus affecting the respiratory tract, with a spectrum of symptoms, from mild infections as fever and cough, to pneumonia and acute respiratory distress syndrome in the most severe cases. However, what is unnerving about the infection is that, its effects are not limited to the respiratory system only. Other organs such as the gastrointestinal (GI) tract and liver seem to be targeted by the virus as well. According to a report, the disease severity can cause haematological changes and even worsen the condition of patients with digestive system diseases.

How does the virus affect the Gastrointestinal system?

Angiotensin converting enzyme II (ACE2) acts as the potential target site transmitting SARS-CoV-2 to humans. ACE2 was found not only highly expressed in the lung alveolar type 2 cells, but also found in oesophagus (food pipe), absorptive enterocytes from ileum (small intestine) and colon large intestine). It is also found in liver and biliary system.

According to a study from Wuhan, 16 percent of patients presented with gastrointestinal symptoms reported:

  • Loss of appetite is the most common symptom.  Nausea and vomiting, Diarrhoea, abdominal pain are the other GI symptoms. 
  • Fecal samples remained positive for SARS-CoV-2RNA for nearly 28 days from the first symptom whereas respiratory samples were positive up to 17 days from the first symptom. It means a patient can continue to shed the Virus RNA in stools in spite of getting cured from respiratory ailments. So, the role of feco-oral route of acquiring the infection cannot be neglected and one needs to follow hygienic practices after using toilets.
  • Liver dysfunction is seen in patients with severe COVID-19 disease. An abnormality in liver function blood test is generally found in COVID-19 symptomatic patients. One of the components in liver function test called as ALT is elevated in them.  ALT elevation was found in 16 to 53% of patients.  However, one need not panic as no cases of acute liver failure have been reported so far.

The above observations highlight the gastrointestinal and liver involvement in COVID-19 patients; however, the final outcome or recovery depends primarily on the management of lung issues. Development of GI symptoms does not indicate the severity of COVID-19 disease.   

Use of immunosuppressant medication in the treatment of COVID-19

One of the other concerns in COVID-19 pandemic is related to immunosuppressant medication which a patient may be taking for some other gastrointestinal and liver diseases like IBD (Crohn’s disease, Ulcerative colitis), Autoimmune hepatitis, etc. If somebody is on steroids, the dose needs to be decreased to the minimal dose possible. Patients who are already taking immunosuppressants like Budesonide, Azathioprine, Methotrexate and Biological therapies are advisable to continue using the same dose as long as the primary disease is under control. However, if the patient is suffering from COVID-19, then only all the immunosuppressant medications mentioned above need to be stopped and alternative medications need to be considered.  

Endoscopy during COVID-19 pandemic

It is important to adopt certain measures related to endoscopy in COVID-19 pandemic so that patients are not unnecessarily exposed to risk of acquiring the infection. This also ensures protection of the endoscopist and other health care workers not to get the infection from patients. 

Screening colonoscopy, endoscopy for dyspepsia and intestinal metaplasia can be postponed for 8 weeks or more and reassess the pandemic and guide the patient appropriately for endoscopic procedures. However, in case of gastrointestinal bleeding, cholangitis, food impaction, perforation, stenting for gastrointestinal obstruction are some of the conditions which can be considered for emergency endoscopic interventions with full PPE for all health care workers. Once the problem is identified, a physical examination and appropriate investigation like labs/USG scan/CT scan or endoscopy should be considered so that the risk of transmission can be minimised.