The colon, or large bowel, has three sides: the ascending colon (right side), the transverse colon, and the descending colon (left side).
The left side of the colon has four sections: the descending colon, the sigmoid colon, the rectum, and the anus.
The primary treatment for colon cancer is surgery. The part of the large bowel with cancer is removed, along with surrounding lymph nodes. Removal of the colon is called a colectomy. The remaining bowel is then joined together. Joining the bowel is called an anastomosis.
When cancer is found in the sigmoid colon, the sigmoid colon is removed. The descending colon is then reconnected to the rectum.
The Sigmoid Colon before surgery. The grey area shows the part of the bowel the surgeon will remove.
The Sigmoid Colon after surgery. The descending colon is now connected to the rectum.
At Cedars-Sinai, the majority of colon and rectal operations are performed using minimally invasive techniques (laparoscopy). Laparoscopy, however, may not be suitable for all patients. Ask your surgeon if you are an appropriate candidate for minimally invasive surgery.
After the surgeon removes the section of the colon, a pathologist evaluates the cancer under a microscope. If the pathologist sees evidence that cancer has spread to the lymph nodes, or if the cancer is a type that grows quickly, the oncologist will usually recommend further treatment with chemotherapy.
After a colectomy, bowel movements might be more frequent. Bowel movements usually become more normal after one year. Your doctor can recommend a bowel care plan to help normalize bowel movements.
The most common time a cancer recurs is within the first two years following diagnosis and treatment. Follow-up care with the surgeon, gastroenterologist and oncologist is important. Periodic checkups may include a physical exam, blood tests, colonoscopy, CT scan or PET scan.