Graduate Institute of Acupuncture Science, China Medical University, Taichung, 40402, Taiwan. Department of Colorectal Surgery, China Medical University Hospital, Taichung, 40447, Taiwan. Department of Colorectal Surgery, China Medical University Hospital, Taichung, 40447, Taiwan. wtchen@mail.cmuh.org.tw. School of Medicine, College of Medicine, China Medical University, Taichung, 40402, Taiwan. wtchen@mail.cmuh.org.tw. Department of Colorectal Surgery, China Medical University Hsinchu Hospital, Hsinchu, 30272, Taiwan. wtchen@mail.cmuh.org.tw.