1 Department of Gastroenterology, People's Hospital of Leshan, Leshan, Sichuan, China; Department of Gastroenterology, Changhai Hospital, Second Military Medical University/Naval Medical University, Shanghai, China; National Clinical Research Center for Digestive Diseases, Shanghai, China. Electronic address: sailnorth@126.com.
2 Department of Gastroenterology, Changhai Hospital, Second Military Medical University/Naval Medical University, Shanghai, China; National Clinical Research Center for Digestive Diseases, Shanghai, China.