A 20mm x 15mm flat polyp in the descending colon requires general anesthesia for surgery. Flat polyps in the descending colon are usually removed by minimally invasive surgery under colonoscopy, in the process of surgical resection there may be a certain degree of pain, coupled with the 20mm x 15mm polyp is still relatively large, the operation time may be long, in order to better and more thorough resection, you need to perform the operation under general anesthesia, the safety of the operation will be higher. In addition, if the pathological results of the polyp show malignancy, it is also necessary to perform general anesthesia to remove the tumor or even part of the descending colon, in order to completely remove the tumor tissue, cancer cells, etc., and to improve the cure rate and therapeutic effect of the patient. There are many surgical options for flat polyps in the descending colon, plus each person’s condition is different, it is recommended that after diagnosis, follow the guidance of a professional doctor.