A colectomy is surgery to remove all or part of the colon (large intestine). It’s one of the most commonly performed abdominal surgeries, with nearly 150,000 elective colectomies performed in the U.S. between 2020 and 2022 alone. The specific type of colectomy depends on where the disease or damage is located, and the surgery can be done through small incisions or a larger open approach.
Types of Colectomy
The name of the procedure tells you which section of the colon is being removed. A right hemicolectomy removes the right side of the colon (the ascending colon), sometimes along with the end of the small intestine and the beginning of the middle section. This is the most common type. A left hemicolectomy removes the left side. In both cases, the remaining portions of the intestine are reconnected so digestion can continue.
A total colectomy removes the entire colon. The small intestine is then connected directly to the rectum, which still allows bowel movements through the anus. A proctocolectomy goes further, removing both the colon and the rectum. This procedure typically requires creating an opening in the abdomen (a stoma) for waste to exit into an external pouch, though surgeons can sometimes construct an internal pouch from the small intestine instead.
Why a Colectomy Is Needed
Colon cancer is one of the most common reasons for colectomy. Removing the affected section of colon, along with nearby lymph nodes, is often the primary treatment. The surgery aims to take out enough tissue to ensure clean margins around the tumor.
Inflammatory bowel diseases like ulcerative colitis and Crohn’s disease can require colectomy when medications stop controlling symptoms or when precancerous changes develop. For ulcerative colitis specifically, removing the colon is considered curative since the disease only affects the colon’s lining.
Diverticulitis, a condition where small pouches in the colon wall become infected or inflamed, is another leading reason for elective colon surgery. Surgery has traditionally been recommended after a second episode, or after a first episode in patients younger than 50. Many people who’ve had diverticulitis report lingering symptoms between flare-ups: bloating, changes in bowel habits, low appetite, and intermittent fevers. These ongoing symptoms often drive the decision to pursue surgery. Other reasons include large polyps that can’t be removed during a colonoscopy, severe bleeding, and bowel obstruction.
Open, Laparoscopic, and Robotic Approaches
Open colectomy uses a single long incision in the abdomen. It gives the surgeon direct access and remains the standard for emergencies or very complex cases. Recovery tends to be longer because of the larger incision.
Laparoscopic colectomy is performed through several small incisions using a camera and long, thin instruments. It results in less pain, shorter hospital stays, and faster recovery for most patients. Robotic surgery uses the same small-incision concept but adds a robotic platform that gives the surgeon a three-dimensional view and instruments that can rotate with greater precision than the human wrist. A meta-analysis of multiple studies found that robotic and laparoscopic approaches produce similar complication rates and hospital stays. Robotic procedures do take about 39 minutes longer on average and are somewhat more likely to be converted to an open procedure mid-surgery, though they result in slightly less blood loss.
Reconnection vs. Stoma
After removing a section of colon, the surgeon either reconnects the remaining intestine (called an anastomosis) or brings the end of the intestine through the abdominal wall to create a stoma. A stoma diverts waste into an external collection bag.
The choice between reconnection and a stoma depends on several factors. If the connection would be made very low in the rectum, the risk of leaking at the junction increases, and a leak can be life-threatening in a frail patient. Roughly 41% of patients who have a low reconnection after rectal cancer surgery experience significant bowel dysfunction a year later, including urgency, frequent bowel movements, and difficulty controlling stool. Prior radiation therapy worsens these outcomes. For some patients, a permanent stoma actually provides better quality of life than a low, unreliable connection. When a stoma is temporary, it’s typically reversed in a second surgery a few months later once the reconnection has fully healed.
Preparing for Surgery
Most colectomy patients start a clear liquid diet the day before surgery. Clear liquids include water, broth, plain tea, and gelatin. Nothing by mouth is allowed for roughly 8 to 10 hours before the procedure.
Bowel preparation, the process of emptying the colon, happens the afternoon and evening before surgery. Your surgical team will prescribe one of several options. The most common home-based prep involves mixing a large-dose laxative powder into 64 ounces of a sports drink and consuming it over about two hours, combined with laxative tablets taken at staggered intervals. Other options include prescription solutions that work similarly. You’ll also be asked to avoid alcohol for two days before surgery. The prep isn’t pleasant, but a clean colon reduces infection risk during the operation.
Recovery After Colectomy
Hospital stays for laparoscopic colectomy typically range from two to four days. Open surgery usually requires a longer stay. The first milestones in the hospital are passing gas and tolerating liquids, both signs that the intestines are waking back up after being handled during surgery.
Diet advances in stages. You’ll start with clear fluids like water and broth, then move to milk-based drinks and smooth juices, then small portions of soft, low-fiber foods. Most people can work back to a normal diet within two to six weeks. The pace depends on how your gut responds. Eating small, frequent meals is easier to tolerate early on than large ones.
At home, most people need four to six weeks before returning to normal activity after a laparoscopic procedure, and somewhat longer after open surgery. Heavy lifting is restricted during this window to let the incisions and internal connections heal. Walking, starting the day after surgery and increasing gradually, is the single most helpful recovery activity.
Long-Term Changes to Expect
If you had a partial colectomy, your remaining colon adapts over time. The colon’s main job is absorbing water, so removing a portion of it means looser and more frequent stools, especially in the first few months. Most people’s bowel habits stabilize within several months as the remaining intestine compensates.
After a total colectomy with the small intestine connected to the rectum, bowel movements are more frequent and watery on a permanent basis. A study of patients who had this procedure found that about 16% experienced stool frequency high enough to significantly disrupt daily life. Neither patient age nor the exact location of the connection appeared to predict who would have this problem.
Adhesions, bands of internal scar tissue that form after any abdominal surgery, are the most common long-term complication. The lifetime risk of being hospitalized for a bowel obstruction caused by adhesions is about 4% after abdominal surgery. Of those who need an operation to fix the obstruction, 10% to 30% develop further adhesions that cause another blockage. Symptoms of adhesion-related obstruction include cramping abdominal pain, vomiting, bloating, and an inability to pass gas or stool.
Complication and Mortality Rates
For elective (planned) colectomy, the in-hospital complication rate is roughly 4% to 5%, and mortality is low, around 0.2% to 0.5%. Urgent colectomies carry higher risk because they’re performed on sicker patients in less controlled circumstances. Complication rates for urgent procedures run between 10% and 12%, with mortality between 2% and 5%. A large study of nearly 150,000 elective colectomies found that surgeons who specialize in colorectal surgery had lower complication and mortality rates than general surgeons performing the same operations, a difference that held true for both elective and urgent procedures.