A novel analysis has demonstrated that the COVID-19 virus isolated from a sick patient's stool can infect and kill the cells in a Petri-dish. This research is a step towards proving a novel transmission route for the infection. If future studies can validate this, it would mean that people could get sick by ingesting a very small quantity of stool from other infected subjects (fecal-oral route of transmission). 

Hepatitis and cholera are other diarrhea disorders that transmit from person to person this way. In COVID-19 patients, gastrointestinal symptoms such as diarrhea and nausea are general. Previous studies have documented that about half of COVID-19 patients have the virus present in their stool. Viral traces seem to remain in stool long after the virus can no longer be spotted in nose and throat swabs.

CDC (Centers for Disease Control and Prevention) suggests offering a sick family member their bathroom to use. A recent study by Brett-Major could not tell if any of the viral material they had found in the stool could make anyone sick.

In China, scientists who mixed a virus solution (isolated from extremely sick COVID-19 patient's stool) with cells reported that it could infect and kill living cells. Approximately 100 times more viruses were observed in feces when compared with samples taken from the patients' mouth and nose. It's still vague if milder infection patients would heavily shed the virus. 

Moreover, the study doesn't reflect real-world transmission since the study used an experimental system. However, in certain clinical settings, the virus present in feces could be a pivotal factor in the disease spread. Probably there are multiple routes of COVID-19 transmission and this might not be a major route.

Virus discharged into the air from coughs and sneezes is the greatest driver of spread. Fomite transmission (contact with contaminated surfaces) may also be playing a role. It's not a bad idea to be cautious in shared bathrooms and closing the lid on the toilet before you flush. Thus, it is important to regularly wash your hands for at least 20 seconds.