Colon and Rectal Cancer

Colorectal cancer is a cancer that starts in the colon or the rectum. Most of these cancers begin as a polyp or growth on the inner lining of the colon or rectum, which is often detected through a diagnostic procedure known as a colonoscopy. In this procedure, a long, flexible tube with a small video camera on the end is inserted through the patient’s rectum and into the colon. The camera transmits images of the lining of the colon on a screen so the doctor can examine it for any abnormalities.

Some polyps can change into cancer over time, but not all polyps become cancer. Surgery is often the main treatment for earlier-stage colon cancers. The type of surgery used depends on the stage of the cancer, where it is, and the goal of the surgery.



Removal of early stage cancer or polyps during a colonoscopy.

Local excision

This is a slightly more extensive procedure that can be used to remove superficial cancers and a small amount of nearby tissue from the wall of colon.


In this procedure, surgeons remove all or part of the colon. Nearby lymph nodes are removed as well.

Hemicolectomy, partial colectomy, or segmental resection

Removal of the part of the colon with the cancer and a small segment of normal colon on either side of the cancer. Usually, about one-fourth to one-third of your colon is removed, but this depends on the size and location of the cancer. The remaining sections of your colon are then reattached. Nearby lymph nodes are removed at this time as well.

Total colectomy involves removing the entire colon.

This procedure is not often needed to treat colon cancer. It is generally used only if there is disease in the part of the colon without the cancer, such as hundreds of polyps (in someone with familial adenomatous polyposis) or inflammatory bowel disease. A colectomy can be done in 2 ways:

  • Open colectomy: The surgery is done through a single long incision in the abdomen.
  • Laparoscopic-assisted colectomy: This minimally invasive procedure requires several small incisions. A laparoscope, a thin lighted tube with a small video camera on the end, is inserted through one of the incisions and enables the surgeon to see inside the abdomen. Special long instruments are inserted through the other incisions to remove part of the colon and lymph nodes.


Similar to a colectomy that’s done to remove the cancer, but instead of reconnecting the segments of the colon, the top end of the colon is attached to an opening (stoma) in the skin of the abdomen to allow stool to leave the body. A removable collecting bag is attached to the stoma to hold the waste.


In this procedure, an opening in the abdominal wall that is made during surgery and the end of the small intestine (the ileum) is connected to a stoma in the skin. A removable collecting bag is attached to the stoma to hold the waste. Once you are healthier, another operation can be done to attach the ends of the colon back together or to attach the ileum to the colon. Rarely, if a tumor can’t be removed or a stent placed, the colostomy or ileostomy may need to be permanent.

Diverting colostomy

Some patients have colon cancers that have spread but also have tumors blocking the colon. For patients with this problem, sometimes surgery is done to relieve the blockage without removing the part of the colon containing the cancer. Instead, the colon is cut above the tumor and attached to a stoma to allow stool to leave the body. This procedure can often help the patient recover enough to start other treatments, such as chemotherapy.

Low anterior resection

This procedure may be performed for advanced rectal cancers. It involves removing the rectum and part of the colon. Radiation and chemotherapy often precede surgery. The rectum is removed, and the colon is attached to the area just above the anal sphincter muscles. Our surgeons can remove even very low (distal) rectal cancers in order to avoid a permanent colostomy.