1 Department of Gastroenterology, Chun'an County First People's Hospital (Zhejiang Provincial People's Hospital, Chun'an Branch), Hangzhou, Zhejiang, P. R. China.
2 Key Laboratory of Gastroenterology of Zhejiang Province, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, P. R. China.
3 Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Traditional Chinese Medicine), Hangzhou, Zhejiang, P. R. China.