Surgical intervention for colon cancer generally involves cutting away the diseased portion of the colon and reconnecting the two healthy sections. The technique, called a surgical resection, resectional surgery, colectomy, or a hemicolectomy, requires that the surgeon fully open the abdomen, resect the colon, remove nearby lymph nodes for analysis, and investigate nearby organs, such as the liver for signs of cancer.

There are currently studies being conducted on the use of laparoscopic surgery, in which only a small opening is made and a tube with instruments and a camera is inserted through the abdominal wall to remove the diseased portion of the abdomen. Because of the high degree of skill required, and the fact that this technique does not allow the surgeon to feel nearby organs, such as the liver, for signs of cancer, this technique is not generally used to cure colon cancer. The technique is used instead in cases requiring the use of palliative surgery to reduce pain in patients with advanced colon cancer, and in cases where the patient is too frail to tolerate general surgery.

Prior to surgery, the patient is generally required to undergo "mechanical bowel prep" which involves not eating any solid foods for one to two days, together with drinking a lavage to clear out any remaining waste material from the colon. Preparation may also involve taking antibiotics to kill bacteria in the colon, and an enema the morning of the surgery. On the day of the surgery, the patient prepared for surgery by administering anesthesia, and inserting a Foley catheter to drain off any urine that collects in the bladder.

If the patient has given his or her authorization prior to the surgery, and the surgeon finds that nearby organs have cancer that are subject to surgical intervention, the surgeon may remove portions of, or the entire organ. In addition, because approximately 2-8 percent of women with colon cancer eventually develop metastasis to the ovaries, a prophylactic oophorectomy may be performed as a preventive measure to avoid later metastasis to the ovaries. While this procedure is a routine option for post- or perimenopausal women, it may not be necessary in premenouposal patients because the incidence of colon cancer for women in this category is rare.

Recovery from surgery normally requires 6-10 days in the hospital. Following the hospital stay, a patient will require 3-4 weeks of additional recovery at home. During this time period, the patient should avoid straining the abdominal muscles (by, for example, avoiding lifting heavy objects) and shold avoid driving so as not to risk any additional trauma to the colon and abdomen.