Pretreatment with transcutaneous electrical acupoint stimulation to prevent postoperative ileus in patients undergoing laparoscopic colon surgery: study protocol for a randomised c... oleh Wei Song, Wei Tang, Rui Feng, Lihua Fan, Jun Guo, Dongli Li, Wenting Chen, Yue Yong, Guijie Yu, Lan Yuan, Guoqiang Fu, Jiangang Song