After removal of the colon tumor, if it is an early stage colon cancer or if there is good bowel preparation it can usually be attached, otherwise a fistula is needed. Otherwise, fistula is needed. Fistula is also a safe and sound operation technique. In early stage colon cancer, after resection, intestinal anastomosis can be directly connected, and fistula is not needed. If the bowel is actively prepared and the colon is clean, the anastomosis can be directly connected. For patients with preoperative intestinal obstruction, due to fecal contamination, direct anastomosis without good intestinal preparation may cause poor healing or anastomotic fistula leakage, resulting in diffuse peritonitis, which may lead to death in severe cases. Fistula should be performed in this case, which can relieve the pressure of the anastomosis and prevent the occurrence of intestinal fistula. Although fistula is not necessary after resection of colon tumor, but in order to avoid the occurrence of enterocutaneous fistula, fistula is currently a safer and more secure method. Therefore, whether to have a fistula or to connect it after colon tumor resection should be decided by the doctor according to the patient’s condition and specific situation.