A colectomy is a type of surgery used to treat colon diseases. These include cancer, inflammatory disease, or diverticulitis. The surgery is done by removing a portion of the colon.
The colon is part of the large intestine. When treating cancer, the surgeon will often remove the part of the colon that appears to have cancer. He or she will also remove another small part on either side of the cancer area. And he or she will remove some nearby lymph nodes. The remaining parts of the colon are then attached to each other. Or an opening to the outside of the body (stoma) is created. This is called a colostomy.