1 Medical School of Chinese PLA, Beijing, China; Department of Gastroenterology, Seventh Medical Center of Chinese PLA General Hospital, Beijing, China.
2 Department of Gastroenterology, Seventh Medical Center of Chinese PLA General Hospital, Beijing, China; Senior Department of Gastroenterology, First Medical Center of Chinese PLA General Hospital, Beijing, China.
3 Section of Gastroenterology, Sacramento VA Medical Center, Mather, California.
4 Department of Gastroenterology, Seventh Medical Center of Chinese PLA General Hospital, Beijing, China.