A colectomy is surgery to remove all or part of the colon (large intestine). It’s one of the most common abdominal surgeries, performed to treat conditions ranging from colon cancer to severe inflammatory bowel disease. The specific type of colectomy depends on which section of the colon is diseased and how much needs to come out.
Types of Colectomy
There are several variations, each defined by how much of the colon is removed:
- Total colectomy removes the entire colon.
- Partial colectomy (segmental resection) removes only a short, diseased segment. The two healthy ends are then sewn or stapled back together to restore normal bowel continuity.
- Right hemicolectomy removes the ascending colon on the right side, and sometimes includes the end of the small intestine and the beginning of the transverse colon.
- Left hemicolectomy removes the left side of the colon, typically from the middle of the transverse colon down through the descending colon, often ending at the upper rectum.
The goal in every case is to take out the damaged or dangerous tissue while preserving as much healthy colon as possible. More colon preserved generally means fewer long-term changes to digestion.
Why a Colectomy Is Needed
Colon cancer is the most common reason for colectomy. Surgeons remove the cancerous segment along with a margin of healthy tissue and nearby lymph nodes to check whether the cancer has spread. In early-stage disease, surgery alone can be curative.
Inflammatory bowel diseases, particularly ulcerative colitis and Crohn’s disease, may require colectomy when medications can no longer control symptoms or when precancerous changes develop. Severe diverticulitis, where small pouches in the colon wall become repeatedly infected or rupture, is another frequent indication. Less common reasons include large polyps that can’t be removed during a colonoscopy, bowel obstruction, and uncontrolled bleeding in the colon.
Emergency colectomies happen when the colon perforates or becomes completely blocked. These are riskier than planned surgeries because there’s no time for preparation, and the patient is often already quite sick.
Open vs. Laparoscopic Surgery
Colectomy can be done through a single large incision (open surgery) or through several small incisions using a camera and specialized instruments (laparoscopic surgery). Robotic-assisted versions of laparoscopic colectomy are increasingly common, giving the surgeon more precise control of the instruments.
Laparoscopic colectomy typically results in less pain, smaller scars, and a faster return to normal activity. Not everyone is a candidate, though. Very large tumors, extensive scar tissue from prior surgeries, or emergency situations may require an open approach. Sometimes a surgery that starts laparoscopically needs to be converted to open if the surgeon encounters unexpected complications.
Preparing for Surgery
For planned colectomies, you’ll go through bowel preparation the day before surgery. This involves drinking a solution that clears out the contents of your colon, similar to what you’d do before a colonoscopy. Current surgical guidelines recommend combining this mechanical cleansing with oral antibiotics taken the night before. The combination significantly reduces the risk of surgical site infections compared to bowel cleansing alone.
You’ll also be asked to stop eating solid food the day before surgery, though some programs allow clear liquids up to a few hours beforehand. Your surgical team will review your medications and may ask you to temporarily stop blood thinners or certain supplements.
What Happens After Surgery
Most people stay in the hospital for several days after colectomy, with laparoscopic procedures generally requiring a shorter stay than open ones. Modern recovery programs focus on getting you moving early, often the same day as surgery, because walking helps the bowel wake back up and reduces the risk of blood clots.
Your diet progresses in stages. On the first day after surgery, you’ll typically start with sips of water. By day two, most programs introduce soft, blended foods. Over the following days, meals gradually increase in calories and protein, progressing from about 900 calories on soft fluids to around 2,100 calories on a more substantial soft diet, before reaching a normal diet by roughly day six. The exact timeline varies depending on how quickly your bowel function returns.
Pain management in the first week relies on a combination of approaches. The goal is to keep you comfortable enough to walk and eat, since both are critical for recovery. Most people can return to light daily activities within two to four weeks after laparoscopic surgery, though full recovery, including the ability to lift heavy objects and exercise without restriction, takes closer to six to eight weeks. Open surgery adds a few weeks to these timelines.
Anastomosis vs. Ostomy
After the diseased section of colon is removed, the surgeon has to decide how to reconstruct things. The two options are reconnecting the remaining bowel (called an anastomosis) or diverting the bowel to an opening in the abdomen where waste collects in an external bag (called a stoma or ostomy).
The decision depends on two key factors: the risk of the connection leaking and whether the patient’s bowel function will be acceptable afterward. An anastomotic leak, where the reconnection doesn’t heal properly, occurs in 2% to 19% of colorectal surgeries and can be a serious, even life-threatening complication. Patients who are malnourished, on certain medications that impair healing, or undergoing emergency surgery face higher leak risks.
When the risk is high, surgeons may create a temporary stoma to give the connection time to heal. After several weeks or months, a second surgery reverses the stoma and restores normal bowel flow. In some cases, particularly after a total colectomy or when the very lowest portion of the rectum is removed, a permanent stoma is necessary. This is a decision made collaboratively between you and your surgeon, weighing the risks and your quality-of-life priorities.
Long-Term Changes to Bowel Function
If you have a partial colectomy with reconnection, your overall bowel function generally remains close to what it was before surgery, with one notable exception: frequency. Research tracking patients after colectomy for colon cancer found that bowel movement frequency increased significantly, with scores rising roughly 45% from preoperative levels. Other aspects of bowel function, including urgency, consistency, and control, did not change significantly for most people.
Men and people who already had frequent bowel movements before surgery were most likely to notice this increase. The colon’s main job is absorbing water, so removing a section means stool passes through faster and retains more moisture. Most people adjust over the first few months as the remaining colon compensates.
After a total colectomy, the changes are more pronounced. Without a colon, stools are looser and more frequent, often four to eight times per day. Dietary adjustments help: eating smaller, more frequent meals, staying well hydrated, and initially avoiding high-fiber and gas-producing foods while the body adapts. Over time, many people find a rhythm that works well for them, though the stool will always be softer than it was with an intact colon.
Potential Complications
Like any major abdominal surgery, colectomy carries risks. Surgical site infections are among the most common, which is why bowel preparation with antibiotics is now standard practice. Anastomotic leaks are the complication surgeons worry about most, as they can lead to abscess formation, sepsis, and the need for additional surgery.
Postoperative ileus, where the bowel temporarily stops moving after being handled during surgery, affects a significant number of patients and is the most common reason for a longer-than-expected hospital stay. Symptoms include bloating, nausea, and an inability to pass gas. It usually resolves on its own within a few days. Other risks include bleeding, blood clots, and injury to nearby organs, though these are uncommon in experienced surgical centers.