While Beijing doctors are busy treating patients with flu and colds, hospitals in Guangzhou, capital of south China's Guangdong province, are seeing a rise in the number of patients with diarrhea.

The number of patients diagnosed with gastroenteritis has increased by 20 percent over the same period last year, said Lu Jianhua, director of the emergency department in the city's First People's Hospital.

Similar increment is also found in other Guangzhou-based hospitals, including the Red Cross Hospital, the People's Hospital and the Third Affiliated Hospital of Guangzhou Medical College.

The phenomenon has caused some to worry over a possible outbreak of norovirus, which has infected over 60,000 people in Japan, but doctors say the phenomenon is not unusual, and the number of gastroenteritis patients usually rises at this time of year.

"Most patients are infected by rotavirus, and the virus has taken advantage of the warm weather in the past few days," said Li Zengqing, a pediatrician in Guangzhou People's Hospital.

Local disease prevention officials said the cases are not connected, and they have not registered any massive outbreak of gastro-viral infections.

"The patients may have been infected after dining in restaurants with poor sanitation, or have eaten undercooked hot-pot food, which is local people's favorite dish in winter," said Wang Zhengwei, a doctor in the Third Affiliated Hospital of Guangzhou Medical College.

Doctors have advised local residents not to eat raw or undercooked foods and refrain from eating too much in the holiday season.

Editor: Yan