Can people transmit coronaviruses like covid in their poop even if they have no symptoms. what about healthy-looking babies and their poopy diapers?

Covid-19 is spread through respiratory droplets. It is not spread through feces, even though fecal matter has the virus in it. Get vaccinated for Covid-19 and issue will cease to be relevant.

Research has found that the COVID-19 virus is present in the feces (poop, stool) of infected people. Theoretically, an infected person can transmit COVID-19 through their feces. However, there are no confirmed cases of this thus the risk is very low. We recommend good handwashing with soap/water for 20 seconds. See https://www.cdc.gov/coronavirus/2019-ncov/faq.html for more details.