1 Department of Anorectal, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan, China.
2 Department of Radiology, The Affiliated Hospital, Southwest Medical University, Luzhou, China.
3 Department of Anorectal, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan, China; Chengdu University of Traditional Chinese Medicine, Chengdu, China. Electronic address: laoshaer@163.com.