This page was reviewed under our medical and editorial policy by

Katherine Poruk, MD, Surgical Oncologist.

This page was reviewed on September 12, 2022.

If you’re diagnosed with colorectal cancer, your doctor may recommend a colectomy, which is surgery to remove all or part of the colon and surrounding lymph nodes. A colectomy, also called colon resection surgery, may also be recommended for other non-cancerous conditions, including Crohn's disease, ulcerative colitis and diverticulitis. A colectomy is a major surgery that requires a lot of healing time, but most patients recover fully and resume normal activities within a few months.

To better understand the need for a colectomy, this quick overview of the digestive system may be helpful:

  • The food you eat ends up in your stomach. It then empties into the small intestine, where much of the digestive process happens.
  • Your small intestine then passes food to the large intestine (or colon), which does the final breakdown and re-asborbs water from your waste.
  • Your large intestine includes the cecum (and the finger-shaped appendix attached to it), the ascending colon, the traverse colon, the descending colon, the sigmoid colon and the rectum.
  • The rectum ends in the anus, the orifice through which waste exits the body.

A colectomy is performed on a portion of the colon and sometimes rectum. The rectum and colon are sometimes called the large bowel, so a colectomy is also known as a large bowel resection.

Why a colectomy is performed

One of the major reasons for a colectomy is to remove cancerous or precancerous lesions. However, several diseases may cause issues that require a colectomy, including:

  • Crohn's disease
  • Severe constipation
  • Intestinal blockages (also known as a bowel obstruction)
  • Diverticular disease
  • Polyps
  • Intestinal injuries
  • Bleeding
  • Twisting of the colon (or volvulus)
  • Ulcerative colitis (UC), as well as other digestive disorders

Types of colectomies

The different types of colectomies are determined by which section or how much of the colon and rectum is being removed:

Hemicolectomy: Doctors remove either the descending colon, the section that travels down the left side or the ascending colon, the section that travels upward on the right side.

Subtotal colectomy: Doctors remove part of the colon but none of the rectum.

Proctocolectomy: Doctors remove the colon and the rectum.

Total abdominal colectomy: Doctors remove the entire large intestine and the small intestine is attached directly to the rectum.

Diverting colostomy: Doctors attach the digestive tract to an opening made in the abdominal wall (a stoma) for waste to exit.

How colectomies are performed

There are two ways that surgeons perform colectomies:

Open colectomy: The surgeon makes a long incision and opens the abdominal cavity.

Laparoscopic-assisted or robotic-assisted colectomy: The surgeon makes small incisions into the abdominal cavity to insert surgical tools and a video camera.

Recovery typically takes longer with an open colectomy, although for either type, you may be in the hospital between two and seven days.

Understanding the risks

Because you’re put under general anesthesia, and a colectomy is major surgery, there are some risks to consider. Be sure to discuss these safety risks with your care team.

  • You may react badly to the anesthetic medications or develop a breathing problem while under anesthesia.
  • During surgery, nearby organs may be damaged, requiring repair or additional surgery.
  • Bleeding during or after surgery, which may require a blood transfusion or a repeat procedure to stop the bleeding
  • Over time, scar tissue may form in the abdomen that blocks the intestines or cause adhesions where the organs stick together, causing twisting, pain and swelling.
  • It may take longer than expected for the bowel to start working again after surgery—a condition called an ileus that may cause nausea or vomiting—and the doctor may delay allowing you to have solid foods. This often requires additional days in the hospital until the ileus resolves.
  • Post-op, you may have:
    • Blood clots in the legs (deep venous thrombosis), requiring treatment with blood thinners
    • Bleeding
    • Infection in the abdomen or at the incision site
    • Hernia at the site of surgery
    • Anastomotic leak (in which the internal wound breaks open)

How to prepare for your colectomy

To prepare for the surgery:

  • Make sure your surgical team and anesthesiologist know about all the medications and supplements you take. Ask how and when you should take your regular medications on the day of surgery.
  • You may need to stop taking drugs that thin your blood, including aspirin, ibuprofen or naproxen.
  • You may be asked to drink only clear fluids and/or stop eating and drinking at a certain time prior to surgery.
  • Stop smoking (since smoking slows healing and creates a higher risk of complications).
  • Alert your surgical team if you’ve developed a cold, flu or other illness prior to surgery.

Additionally, in the days leading up to surgery, your doctor may recommend bowel preparation, which may include a liquid diet, enemas and potentially laxatives to clear your bowel.

What to expect the day of surgery

During a colectomy, an anesthesiologist administers drugs to help you fall asleep, stay asleep and feel no pain (called general anesthesia). The surgery itself may take up to four hours, and you may be in the hospital recuperating for two to seven days.

The actual surgery differs depending on the surgical approach (either open or minimally invasive).

  • In an open colectomy, the surgeon cuts 6 to 8 inches long along the abdominal cavity.
  • In a laparoscopic surgery, which only requires a few small cuts, the surgeon inserts instruments and a video camera. To do so, the surgeon fills the area with gas to see better.

In either surgical method, the surgeon inspects the large intestine and removes diseased areas and nearby lymph nodes.

If there's enough healthy large intestine left, these two ends may be brought together and stitched or stapled in a procedure called an anastomosis. If there’s not enough healthy intestine or there are concerns about the healing of the anastomosis, the surgeon attaches the open end of the digestive tract to the abdominal wall. This attachment creates a stoma, to allow waste to pass out of the body. If this surgery connects the colon to the abdomen, it’s called a colostomy. If it connects the small intestine to the abdominal wall, it’s an ileostomy. These attachments may be either short-term or permanent.

What to expect after the procedure

After surgery, you may recover in the hospital for several days, up to a week. You may only be able to drink clear liquids for the first few days. Eventually, your diet expands to thicker fluids and soft foods.

To help you heal, your care team may provide specific instructions based on:

  • Which surgery was performed and why
  • How the surgery was performed
  • How much colon was removed
  • Whether or not you have a stoma 

Home care after colectomy

When you go home, you may still be in pain for potentially up to several weeks. This is especially true if you cough, sneeze or make sudden movements.

To ease pain and expedite healing:

  • Take it slow
  • Try to take short walks
  • Don’t push yourself
  • Take your pain medication regularly (and avoid driving while you’re on it)

Bowel movements may be difficult and potentially painful at first. Your feces may be hard, and you may not be able to move your bowels at all, or they may get looser. If you’re constipated (a possible side effect of pain medication or some foods as you recover), try:

  • Taking a walk or being active
  • Easing up on narcotic pain medications
  • Asking your doctor about stool softeners
  • Asking about milk of magnesia or other laxatives
  • Asking about high-fiber foods

Eating may also be challenging at first. Try to eat small amounts of food several times a day, but avoid foods that typically cause gas, loose stools or constipation. You are also encouraged to remain well-hydrated throughout the day.

When to call your doctor post-op

Call your care team once you're home if you experience:

  • Vomiting
  • Diarrhea
  • Fever over 101℉
  • Swelling in your abdomen or legs
  • Constipation for more than four days
  • Black, tarry or bloody stools
  • Chest pains
  • Shortness of breath
  • Changes in the site of your surgery such as redness or bleeding

Long-term expectations

Your long-term expectations differ based on the extent of your procedure and whether you’ve had a colostomy or ileostomy. If you underwent a total abdominal colectomy, you may have four to six bowel movements a day after recovery.

If you had a colostomy or ileostomy, you may need to use bags to collect your stool. A specially trained ostomy nurse or enterostomal therapist may show you how to care for your stoma and where to order supplies. You may have the colostomy or ileostomy reversed in two to six months, or it may be permanent.

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