INTRODUCTION Colorectal cancer rates are rising, with surgery emphasizing radical resection and vessel ligation. Conventional methods using clips pose risks of bleeding and complications. Ultrasonic scalpels offer a safer alternative, approved for various surgeries, but their efficacy in colorectal cancer surgery needs prospective validation. STUDY OBJECTIVE Study compares safety/efficacy of clipless vs. clip-type hemostasis using ultrasonic scalpel in colorectal surgery, focusing on post-op bleeding frequency, intraoperative bleed, drainage, hospital stay. STUDY DESIGN This study is a prospective, randomized, single-center study comparing clipless ultrasonic energy-based hemostasis versus conventional clipping hemostasis in performing laparoscopic colectomy. The study's experimental group undergoes surgery with an ultrasonic scalpel, while the control group receives treatment with a monopolar energy device and clips. Allocation to groups, using a 1:1 ratio, is randomized via a computerized table by a blinded coordinator, immediately post-anesthesia. Principal investigators and administrators remain blinded throughout the study. STUDY POPULATION 1\. Screening A detailed review of the medical records will be performed to assess inclusion/exclusion criteria for all subjects who have been diagnosed with colonic adenocarcinoma and are subject to a colectomy procedure. All patients who are eligible, meet the inclusion and none of the exclusion criteria of this study, will be offered enrollment into the study at each site. RISK ANALYSIS The surgical procedure, postoperative care, and follow-up will be the same for the experitmental and control groups in this study. The use of the ultrasonic scalpel alone may prevent complications such as clip-induced intestinal obstruction, infection, bleeding from clip dislodgement, bile leakage, and infection, but there is no additional benefit for other subjects. The risk of bleeding when ligating vessels with an ultrasonic scalpel has been demonstrated to be safe in retrospective studies for vessels 7 mm or less (8-17). Vessels larger than 7 mm are ligated using surgical clips because the safety of ligation with the ultrasound scalpel has not been studied. Based on the reported safety of this method of ligation, the risks do not outweigh the benefits when analyzed in the aggregate. QUALIFICATION OF PARTICIPATING SURGEONS 1. Surgical procedure * Laparoscopic surgery: Surgery for colorectal cancer consists of ligating blood vessels to the lesion, detaching or mobilizing the colon, and resecting and anastomosing the bowel. * Clipless ultrasound energy-based hemostasis arm: the ultrasound scalpel is used to dissect and ligate the vessel, but clips are used for vessels larger than 7 mm in diameter. If there is significant bleeding during the procedure, surgical clips and hemostatic agents may be used for patient safety at the discretion of the surgeon. * Control arm: a combination of monopolar cautery and surgical clips will be used for vascular ligation and lymph node dissection. 2. Procedure standardization and qualification procedure This study is about laparoscopic surgery for colorectal cancer and all surgeries will be performed by surgeons with at least 100 laparoscopic colorectal cancer surgeries. STATISTICAL ANALYSIS This study compares the frequency of postoperative bleeding between clipless and clip-type ultrasound energy hemostasis in laparoscopic colorectal cancer surgery, assuming that there will be deviations from randomization, such as switching of surgical groups after randomization or additional vessel ligation with clips during or after surgery, we will perform a per-protocol analysis. The missing values of postoperative bleeding, intraoperative blood loss, intraoperative blood transfusion, and conversion to laparotomy are assumed to be none, and the missing values of postoperative drainage tube hematocrit and drainage tube triglycerides are converted to the mean values of the same group. Outliers will be retained without replacement for intraoperative blood loss, operative time, maximum postoperative plasma hemoglobin decline, and total drainage volume within 5 days postoperatively. For Type 1 errors, the frequency of postoperative intra-abdominal bleeding in the control group will be analyzed during data safety monitoring every 50 cases to ensure that it is less than 0.5-4.5% according to the literature.