In colon resection, a portion of the colon is removed (resected) during surgery. The most common types of colorectal resection are listed below.

Right Hemicolectomy Part or all of the ascending colon and cecum are removed. The colon is then reconnected to the small intestine.	Left Hemicolectomy Part or all of the descending colon is removed. The transverse colon is then reconnected to the rectum.
Sigmoid Colectomy Part or all of the sigmoid colon is removed. The descending colon is then reconnected to the rectum.	Low Anterior Resection The sigmoid colon and a portion of the rectum are removed. The descending colon is reconnected to the remaining rectum.

Abdominal Perineal Resection

Part or all of the sigmoid colon and the entire rectum and anus are removed. A colostomy is then performed.

Colostomy

After certain types of surgery, the colon and rectum may need to be kept clear of stool while they heal. In other cases, the rectum has been removed or can’t be reconnected to the rest of the colon. In either case, a colostomy is needed. This creates a new opening in the abdomen so waste can leave the body. You may need the new opening for a short time, or permanently. If you had a colostomy during colorectal surgery, your health care providers will help you learn how to care for it.