1. Department of Gastroenterology, The Second Clinical Medicine College (Shenzhen People's Hospital) of Jinan University, Shenzhen, Guangdong 518020, P.R. China
2. Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai 200433, P.R. China
3. Department of General Surgery, Shenzhen Children's Hospital, Shenzhen, Guangdong 518020, P.R. China