New studies show that it’s not just the lungs that can be severely affected by COVID-19. Researchers at Massachusetts General Hospital and Harvard Medical School examined abdominal scans of over 400 patients with the disease and discovered bowel abnormalities such as thickened bowel walls and gas cysts in the gastrointestinal tract.

The researchers speculated that the abnormalities which resembled dying bowel disease were caused by blood clotting and small vessel injury, a complication that has been noted as a side effect of COVID-19. According to Newsweek, Dutch researchers recently discovered that the virus can infect and replicate in the cells of the intestine.

The researchers revealed that the SARS-CoV-2, the virus that causes COVID-19, enters the body by attaching itself to an enzyme called angiotensin-converting enzyme 2 (ACE2) which is found in the human gut as well as the respiratory system. According to a Chinese study, researchers found that digestive symptoms, especially diarrhea, were common among COVID-19 patients.

Brennan Spiegel, professor of medicine and public health at Cedars-Sinai and co-author of The American Journal of Gastroenterology, told Newsweek:

“I think the main message is COVID-19 is not just a cough. We are starting to learn from our colleagues in China and around the world that there’s a large group of people who may not ever report for care, or at home with digestive symptoms — diarrhea, nausea, vomiting, less so abdominal pain but that too, low appetite — who are struggling to determine if they have COVID-19 or not.”