A hemicolectomy is a surgery that removes roughly half of your colon (large intestine). The procedure is most commonly performed to treat colon cancer, though it’s also used for inflammatory bowel disease, large polyps with cancer potential, bowel obstructions, and certain emergencies like a perforated colon. “Hemi” means half: a right hemicolectomy removes the right side of your colon, while a left hemicolectomy removes the left side. After the diseased section is taken out, the surgeon reconnects the remaining bowel so your digestive system can function without a permanent external bag.
Right vs. Left Hemicolectomy
Which half gets removed depends on where the problem is located. The right side of the colon handles most of the water absorption from digested food, while the left side mainly stores and moves stool toward the rectum. A right hemicolectomy removes the cecum (where the appendix attaches), the ascending colon, and part of the transverse colon. A left hemicolectomy removes the descending colon and sometimes part of the sigmoid colon. An “extended” version of either procedure takes out a larger portion when needed, such as when a tumor sits near the middle of the transverse colon.
The distinction matters beyond just anatomy. Because the right colon absorbs water, removing it tends to produce looser stools afterward. Patients after right hemicolectomy are roughly three and a half times more likely to have liquid or mushy stools compared to the general population of the same age (17.2% vs. 4.8%). Left hemicolectomy patients generally don’t experience this same shift in stool consistency.
Why It’s Performed
Colon cancer is the most common reason. When imaging and biopsy confirm a tumor in one half of the colon, removing that section along with nearby lymph nodes gives the best chance of clearing the cancer and staging it accurately. But hemicolectomy also treats a range of other problems: inflammatory bowel disease that hasn’t responded to medication, a twisted colon (cecal volvulus), complicated appendicitis that involves the base of the cecum, diverticular disease isolated to one side, and ischemic colitis where blood flow to part of the colon has been cut off.
Sometimes the surgery is unplanned. A colonoscopy that accidentally perforates the bowel wall, a colon cancer that causes a sudden obstruction, or a traumatic injury can all require an emergency hemicolectomy. Urgent cases carry higher complication rates than planned surgeries, so when the underlying condition allows it, surgeons prefer to schedule the procedure electively.
Open, Laparoscopic, and Robotic Approaches
There are three ways to perform a hemicolectomy, and the choice affects your incision size, recovery, and complication risk. Open surgery uses a single large incision across the abdomen. Laparoscopic surgery uses several small incisions for a camera and instruments, plus a slightly larger incision (often along the midline) to remove the specimen. Robotic surgery uses a similar approach but with articulating robotic arms controlled by the surgeon at a console.
Laparoscopic surgery became the standard minimally invasive approach, but it has some limitations. The instruments are rigid and don’t bend, which makes delicate dissection around blood vessels more difficult. In most laparoscopic right hemicolectomies (about 89% of cases), the surgeon still needs a midline incision to reconnect the bowel and extract the removed tissue. That midline incision carries a roughly 10.6% chance of developing a hernia later.
Robotic platforms like the da Vinci system address some of these drawbacks. The articulating instruments allow the surgeon to reconnect the bowel entirely inside the body, which means the specimen can be extracted through a smaller, off-midline incision. When an off-center incision is used instead of a midline one, the hernia rate drops to about 0.9%. Robotic surgery also makes it easier for the surgeon to perform a more thorough lymph node removal, which is important for accurate cancer staging.
How the Bowel Gets Reconnected
After the diseased portion is removed, the two remaining ends of bowel need to be joined together. This connection is called an anastomosis, and it’s the most critical step of the operation. There are two main methods: hand-sewn suturing and mechanical stapling.
In planned (elective) surgeries, stapled connections outperform hand-sewn ones across several measures. Stapling shortens the overall surgery time, leads to earlier return of bowel sounds, results in fewer wound infections, and is associated with lower leak rates. Hospital stays tend to be shorter as well. Pain levels are similar between the two methods.
In emergency surgeries, however, these advantages largely disappear. The differences in surgery time, bowel recovery, and infection rates between stapled and hand-sewn connections are not statistically significant when the operation is urgent. This is one more reason elective surgery tends to produce better outcomes overall.
Complication Rates
The most feared complication is an anastomotic leak, where the reconnection point fails to heal properly and bowel contents seep into the abdomen. For right hemicolectomy, the overall leak rate is about 2.1%. Several factors push that number higher: emergency surgery, an extended resection that removes more colon than a standard procedure, and conversion from a laparoscopic approach to an open one mid-surgery.
Other complications include prolonged ileus (when the bowel is slow to “wake up” and resume normal movement), pneumonia, wound infection, and bleeding at the anastomosis site. Patients with significant underlying health problems and those requiring urgent surgery face the highest risk of serious outcomes, including in-hospital mortality.
Hospital Stay and Early Recovery
Most patients stay in the hospital for three to four days after a hemicolectomy. Modern recovery protocols, known as Enhanced Recovery After Surgery (ERAS), are designed to get you eating and moving as quickly as possible because early activity reduces complications like blood clots and ileus.
The typical diet progression moves fast. On the first day after surgery, you’ll start with sips of water. By day two, you’ll move to a soft blended diet (around 1,100 calories with moderate protein). Day three introduces a soft fluid diet, and by day four, most patients are eating a normal diet of about 2,200 calories. This is a significant shift from older practices that kept patients on clear liquids for days. The key milestone for discharge is passing gas or having a bowel movement, which signals your intestines are functioning again.
You should be able to return to your normal daily routine within one to two weeks, though heavier physical activity and lifting restrictions typically last longer. Your surgical team will give you specific guidance based on your incision type and overall condition.
Long-Term Bowel Changes
Your colon will work differently with a significant portion removed, and the changes depend on which side was taken out. After a right hemicolectomy, stools tend to be noticeably looser because the right colon is where most water absorption happens. The remaining colon does adapt over time, but research shows that liquid or mushy stools and fecal urgency remain more common in right hemicolectomy patients long after surgery. About 6.6% of right hemicolectomy patients report ongoing liquid incontinence, compared to less than 2% of those who had a left-sided or sigmoid resection.
Stool frequency, interestingly, does not differ significantly between right and left hemicolectomy patients. You won’t necessarily go to the bathroom more often, but the consistency of what you pass will likely be softer. For many people, dietary adjustments like reducing high-fiber or gas-producing foods and eating smaller, more frequent meals help manage these changes. Some people find that bowel function improves gradually over the first year as the remaining colon compensates.
After a left hemicolectomy, long-term changes are generally less pronounced. The right colon continues to absorb water normally, so stool consistency stays closer to what it was before surgery. The main adjustment is that the shorter colon has less storage capacity, which can mean slightly more frequent trips to the bathroom until the body adapts.