1. Department of General Surgery, The First People's Hospital Xianyang City, Xianyang, Shanxi 712000, P.R. China
2. Department of Endocrinology, The First People's Hospital Xianyang City, Xianyang, Shanxi 712000, P.R. China
3. Department of Anorectal, The First People's Hospital Xianyang City, Xianyang, Shanxi 712000, P.R. China