Department of Gastroenterology;
Shandong Provincial Hospital Affiliate to Shandong University;
Jinan 250021;
Shandong Province;
China;
Department of Gastroenterology;
Taian City Central Hospital;
Taian 271000;
Shandong Province;
China;
Department of Gastroenterology;
Central Hospital of Zibo;
Zibo 255036;
Shandong Province;
China;
Department of Gastroenterology;
Laiwu City People’s Hospital;
Laiwu 271100;
Shandong Province;
China;
Qingdao Municipal Hospital;
Qingdao 266071;
Shandong Province;
China;
Department of Gastroenterology;
Affiliated Hospital of Jining Medical University;
Jining 272100;
Shandong Province;
China;
Department of Gastroenterology;
Jinan Central Hospital;
Jinan 250013;
Shandong Province;
China;
Department of Gastroenterology;
Dongying City People’s Hospital;
Dongying 257091;
Shandong Province;
China;