A colon resection is a surgery that removes part or all of the large intestine (colon) to treat disease or prevent cancer. Also called a colectomy, it’s one of the most commonly performed abdominal surgeries, used for conditions ranging from colorectal cancer and inflammatory bowel disease to severe diverticulitis and bowel obstructions. The surgeon removes the diseased section and, in most cases, reconnects the healthy ends so the digestive tract continues to function.
Why a Colon Resection Is Needed
The most frequent reason for colon resection is colorectal cancer. Removing the tumor along with a margin of healthy tissue gives the best chance of eliminating the disease. Beyond cancer, the procedure treats several other serious conditions:
- Inflammatory bowel disease. Ulcerative colitis and Crohn’s disease sometimes stop responding to medication. Crohn’s disease most often requires surgery for bowel obstructions caused by scarring, followed by abscesses and abnormal connections between organs (fistulas). Ulcerative colitis may require removal of the entire colon when symptoms can’t be controlled.
- Diverticulitis. Repeated or complicated infections in small pouches along the colon wall can require removing the affected segment, most often the sigmoid colon.
- Bowel obstruction. A blocked colon is a surgical emergency that may call for partial or total removal depending on the cause and extent.
- Precancerous polyps. People with genetic conditions that cause hundreds of polyps sometimes choose a total colectomy to prevent cancer before it develops.
- Perforation or severe bleeding. A hole in the colon wall or uncontrolled bleeding are absolute indications for surgery regardless of the underlying disease.
Types of Colon Resection
The specific name depends on which segment of the colon is removed. A right hemicolectomy takes out the ascending colon on the right side and is the most commonly performed type. It sometimes includes the end of the small intestine and the beginning of the transverse colon. A left hemicolectomy removes the descending colon on the left side.
A sigmoid colectomy (sigmoidectomy) removes the S-shaped curve that connects the colon to the rectum and is common in diverticulitis cases. A segmental resection takes out only a short diseased section, with the two healthy ends reconnected. A total colectomy removes the entire colon and connects the small intestine directly to the rectum so bowel movements can still pass naturally.
Open, Laparoscopic, and Robotic Approaches
Surgeons can perform a colon resection through a single large incision (open surgery) or through several small incisions using a camera and specialized instruments (laparoscopic or robotic surgery). The minimally invasive approaches offer real advantages: lower rates of complications and death compared to open surgery, along with shorter hospital stays and lower overall costs. Laparoscopic surgery is the least expensive option, with hospital charges averaging about $21,000 less than open surgery.
Robotic surgery uses the same small-incision concept but gives the surgeon more precise instrument control. It has a notably lower rate of needing to convert mid-surgery to an open procedure (about 1.5% versus 13.3% for laparoscopic). The tradeoff is cost: robotic procedures average roughly $15,500 more than laparoscopic ones. In terms of complication rates, laparoscopic and robotic approaches perform similarly. Your surgeon will recommend the approach based on the complexity of your case, the location of the disease, and what’s available at your hospital.
What Happens During Surgery
After general anesthesia, the surgeon identifies and removes the diseased section of the colon. In most cases, the two remaining ends are then sewn or stapled together, a connection called an anastomosis. This restores the digestive tract so stool passes through your body as it did before, minus the removed segment.
When the remaining ends can’t be safely reconnected, usually because of severe inflammation, infection, or a very low connection near the anus, the surgeon creates a stoma. This is an opening in the abdominal wall where the intestine is brought to the surface, and waste collects in an external pouch. A loop colostomy is typically temporary, giving the downstream bowel several months to heal before a second surgery reconnects everything. An end colostomy is usually permanent but can sometimes be reversed. A permanent stoma is most often needed when the rectum or anus has been removed, as in some advanced cancers.
Risks and Complications
Like any major surgery, colon resection carries risks. The most closely watched complication is an anastomotic leak, where the reconnection site fails to heal properly and intestinal contents seep into the abdomen. Leak rates depend heavily on where the connection is made. Low-risk connections between sections of small intestine leak about 1 to 2% of the time, while connections very close to the anus leak in 5 to 19% of cases. For a typical colon cancer resection, a large study of over 1,700 patients found an overall leak rate of about 5%.
Leaks are usually detected around 8 to 9 days after surgery, though they can appear anywhere from 2 to 42 days out. When a protective temporary stoma is used for higher-risk connections, leak rates drop significantly (roughly 10% versus 23% without one), and the need for reoperation is much lower. Other potential complications include infection at the incision site, blood clots, and a temporary slowdown of bowel activity where the intestines are sluggish to resume normal movement after surgery.
Recovery Timeline
Most people stay in the hospital 3 to 4 days after a laparoscopic colon resection. Under accelerated recovery programs, some patients meeting specific criteria, including tolerating a soft diet, managing pain with oral medication, and passing gas or stool, go home as early as day two. Open surgery typically means a longer stay. A first follow-up visit is usually scheduled around a week after surgery, with a second at about three weeks.
Eating resumes in stages. You’ll start with clear fluids like water, weak tea, and broth, then progress to milky drinks and smooth juices. From there, you move to a light diet of small portions of soft, low-fiber foods that are easy to digest. Most people can gradually return to their normal diet within 2 to 6 weeks. Rushing this process can cause cramping, bloating, or diarrhea, so building up slowly matters.
Full physical recovery, including a return to work and normal activity, varies by the approach used and your overall health. Minimally invasive surgery generally allows a faster return, often within 2 to 4 weeks for desk-type work, while open surgery recovery takes longer.
Long-Term Changes in Bowel Function
After a partial colectomy, most people find their bowel habits shift somewhat. Bowel movement frequency tends to increase after surgery. Some people experience looser stools, occasional urgency, or episodes of leakage, particularly in the early months. Excessive straining and stool fragmentation (passing small amounts multiple times) are also possible.
The encouraging finding is that these changes tend to stabilize. Research tracking patients for a median of 16 months after colon cancer surgery found significant improvement in stool-related symptoms like pain during bowel movements, bleeding, and skin irritation around the anus. Overall bowel function scores showed no meaningful decline from pre-surgery levels. Some studies do report decreased social functioning and increased diarrhea symptoms, but for many patients, the relief from the original disease outweighs the adjustments. After a total colectomy, where the small intestine connects directly to the rectum, more frequent and looser stools are expected as a permanent change, since the colon’s primary job is absorbing water.