1. Department of Gastroenterology; The General Hospital of Beijing Military Command; Beijing China
2. Dalian Medical University; Dalian China
3. Department of Anorectal Surgery; The Eighth Hospital; Wuhan Hubei China
4. Ba Yi Children's Hospital; The General Hospital of Beijing Military Command; Beijing China
5. Division of Gastroenterology; Washington University School of Medicine; St. Louis MO USA