1 Department of Pediatric Surgery, Yichang Central People's Hospital, Yichang, China.
2 Institute of Digestive Disease, China Three Gorges University, Yichang, China; Department of Gastroenterology, Yichang Central People's Hospital, Yichang, China.
3 Institute of Digestive Disease, China Three Gorges University, Yichang, China; Department of Gastroenterology, Yichang Central People's Hospital, Yichang, China. Electronic address: liuwei@ctgu.edu.cn.