Anal coronavirus swabs are now mandatory for anyone coming to China, despite objections from foreign governments.
The “humiliation tests” involve inserting a cotton swab 3 to 5 centimeters (1.2 to 2.0 inches) into the anus and gently twisting it.
Beijing claims it is a more effective way of detecting Covid, but critics say it has left people with “psychological distress”.
The swab tests were previously used in areas of China where outbreaks have occurred. However, they are now being expanded to include airports, including Beijing and Shanghai.
Infectious disease doctor Li Tongzeng said traces of virus in anal swabs and stool samples could remain detectable longer than in upper respiratory samples.
Such wiping “can increase the detection rate of infected people,” the chief doctor of Beijing Youan Hospital told CCTV.
Researchers from the Chinese University of Hong Kong (CUHK) said stool tests might be most effective at identifying Covid-19 in children.
In an article published in 2020, CHUK experts said that children and infants have higher viral loads in their feces than adults.
A throat swab on a 52-year-old man in Weinan, a city in northern Shaanxi Province, reportedly showed a negative result despite exhibiting several tell-tale symptoms of Covid.
The patient, who developed a cough and had a loss of appetite, retested with anal and nasal swabs, which came back positive.
Dr. Li added that anal samples are only required for key groups like those in quarantine.
As CCTV said, officials are unlikely to condone the use of anus tests on the same scale as other methods because it is “not convenient”.