Shi-hua Zheng1, Qiao-yun Tong, Zong-yao Zhu, Zhong-yan Li, Hui You. 1. The First College of Clinical Medical Sciences, China Three Gorges University, Department of Gastroenterology, Yichang Central People's Hospital, Yichang 443003, Hubei, China. zshua2004@yahoo.com.cn