Patient: My father was found to have sigmoid colon adenocarcinoma by colonoscopy on December 14, 2008, and the sigmoid colon cancer was removed by surgery on the 19th. How many courses of chemotherapy should be done after surgery? My father is recovering well from the wound, can he return it now? Post-operative chemotherapy for gastrointestinal tumors usually takes 6-8 courses, which is about half a year. Colostomy closure surgery can be performed 3 months after surgery, but since chemotherapy itself may have an effect on the colonic anastomosis, my suggestion is that it is better to perform surgery after chemotherapy is finished.