China has made it compulsory for foreign travelers to that country to undertake anal swab tests for COVID-19.
The move has angered many visitors who consider it inconvenient and even psychological traumatic.
Beijing, Shanghai and the port city of Qingdao are some of the cities requiring the checks, in addition to nasal or throat swab tests.
The anal swab test is compulsory for some international arrivals, state media has reported.
According to the Chinese Center for Disease Control the test is performed with a sterile cotton swab.
The swab looks like a very long ear bud, that is inserted 3 cm to 5 cm (1.2 inches to 2 inches) into the anus before being gently rotated out.
Chinese doctors say such tests ensure that infections are spotted, since coronavirus traces can be detectable in the anus for longer than in the respiratory tract.
Many countries have complained including Japan, with the government saying Japanese travellers to China who took the anal test have suffered “great psychological pain”.
Meanwhile South Korean visitors can now submit stool samples instead of “Chinese authorities taking them directly”, Choi Young-Sam, a spokesman of the South Korean foreign ministry, said last week.
The World Health Organization (WHO) has only however recommended testing of respiratory tract specimens, where possible, to diagnose respiratory diseases.
Spokesman Christian Lindmeier is quoted as saying that “Faecal samples may offer an alternative testing material, especially in patients with gastrointestinal symptoms,” but they are “less likely than respiratory samples to be positive in the first week of symptoms.”