TAIPEI (Taiwan News) — For some people infected with SARS-CoV-2, the virus that causes the Wuhan coronavirus (COVID-19), the first sign of illness is gastrointestinal symptoms, particularly diarrhea, according to a study published in the American Journal of Gastroenterology on March 30.

Although most coronavirus patients first exhibit a cough, shortness of breath, or sore throat, digestive symptoms also occur in patients with mild disease severity. The study found that those who exhibit digestive symptoms early on may be more likely to develop respiratory symptoms fever later — or not at all. The findings are important because this subgroup may go undetected, unwittingly spreading the illness to others, according to the researchers.

Conducted by Chinese researchers, the study analyzed data from 206 coronavirus patients at a hospital in China's Hubei province. Of the 206 patients, 48 (23 percent) exhibited digestive symptoms only, 89 (43 percent) had only respiratory symptoms, and 69 (33 percent) presented with both digestive and respiratory symptoms.

Among the two groups with digestive symptoms (117 patients), diarrhea was observed in 67 of them, of whom 19.4 percent had as their first symptom, according to the study. Diarrhea lasted from one to 14 days, with an average duration of five days and an average of four bowel movements per day.

After the onset of typical coronavirus symptoms, patients with digestive discomfort sought medical care later than those with just respiratory symptoms (an average of 16 days vs. 11 days).

The study also found that virus infected patients with digestive symptoms were more likely to test positive for the coronavirus in their stool, have delayed diagnoses, and take longer to clear the virus from their bodies compared to patients with only respiratory symptoms.

The authors, therefore, suggested that “patients with new-onset digestive symptoms after a possible COVID-19 contact should be suspected for the illness, even in the absence of cough, shortness of breath, sore throat, or fever.”