Colon cancer surgery removes the cancer and a margin of healthy tissue, along with nearby lymph nodes. Surgeons may remove part of the colon (a colectomy) or, in rarer cases, the whole colon, depending on the tumour’s size, location and stage. The three phases—preparation, operation and recovery—are carefully managed to give you the best possible outcome.

If you or a loved one has been told that surgery is the next step, it’s natural to feel anxious. You might have questions swirling in your head: What exactly will they do? How long will it take? What will recovery feel like?

This blog walks you through the whole journey, step by step. Earlier posts in this series covered the early warning signs of colon cancer, the tests used to diagnose it, and the treatment options available, including chemotherapy. Here, we focus on surgery—the most common and often the most effective treatment for colon cancer.

By the end, you’ll understand the main types of operation, how surgeons decide whether to remove part or all of the colon, and what to expect before, during and after your procedure. Knowledge tends to ease worry, so let’s take it one stage at a time.

What are the main types of colon cancer surgery?

Surgery for colon cancer isn’t one-size-fits-all. The right operation depends on where the tumour sits, how big it is, and whether the cancer has spread. Below are the most common procedures your surgical team may discuss with you.

Polypectomy and local excision

For very early cancers—those still contained within a polyp—surgeons can often remove the growth during a colonoscopy. This is called a polypectomy. If the area is slightly larger, a local excision removes the polyp along with a small amount of surrounding tissue.

Both procedures are minimally invasive. There are no cuts in the abdomen, and recovery is usually quick. This option suits patients whose cancer was caught at the earliest possible stage.

Partial colectomy (segmental resection)

A partial colectomy is the most common surgery for colon cancer. The surgeon removes the section of colon that contains the tumour, plus a margin of healthy tissue on either side. Nearby lymph nodes are taken out too, so they can be checked for cancer cells.

Once the diseased section is gone, the surgeon usually rejoins the two healthy ends of the colon. This connection is called an anastomosis. Most people who have a partial colectomy keep normal bowel function after they heal.

Total colectomy

A total colectomy removes the entire colon. This is far less common and is generally reserved for specific situations—for example, when a patient has multiple tumours, or an underlying condition such as familial adenomatous polyposis (FAP) or ulcerative colitis that raises the risk of further cancers.

Because the whole colon is removed, the surgeon connects the small intestine to the rectum, or creates a stoma (an opening on the abdomen) if the rectum also needs to be removed.

Colostomy and ileostomy

Sometimes the two ends of the bowel can’t be safely rejoined straight away. In these cases, the surgeon creates a stoma, bringing part of the bowel to the surface of the abdomen. Waste then collects in a small bag worn outside the body.

A stoma may be temporary—giving the bowel time to heal before a second operation reconnects it—or permanent. Many people worry about life with a stoma, but with support from a specialist stoma nurse, most adjust well and return to their usual activities.

Open surgery versus keyhole (laparoscopic) surgery

Colon operations can be performed in two ways. Open surgery uses one larger incision in the abdomen. Keyhole (laparoscopic) surgery uses several small incisions and a tiny camera to guide the surgeon.

Keyhole surgery often means less pain, smaller scars and a faster recovery. However, open surgery may be the safer choice for larger tumours or complex cases. Your surgeon will recommend the approach best suited to your situation.

How does the surgeon decide whether to remove part or all of the colon?

This is one of the most common questions patients ask, and the answer comes down to several factors your surgical team weighs up carefully.

• Tumour location: The colon has several sections. Where the tumour sits determines which part needs removing—for example, a right hemicolectomy for a tumour on the right side, or a left hemicolectomy for one on the left.
• Tumour size and stage: Larger or more advanced tumours may require a wider resection to ensure clear margins.
• Number of tumours: Multiple tumours in different parts of the colon may make a total colectomy the safer option.
• Underlying conditions: Genetic syndromes like FAP, or long-standing inflammatory bowel disease, raise the lifetime risk of new cancers. In these cases, removing the whole colon can be the wiser long-term choice.
• Whether the cancer has spread: If cancer has reached the liver or other organs, surgery may be combined with other treatments, and the plan is tailored accordingly.

In short, surgeons aim to remove all the cancer while preserving as much healthy bowel—and normal function—as possible. Removing the whole colon is only recommended when keeping part of it would leave you at real risk.

What happens before colon cancer surgery?

Good preparation makes surgery safer and recovery smoother. Here’s what typically happens in the days and weeks leading up to your operation.

Pre-operative assessment

You’ll have a series of checks to confirm you’re fit for surgery. These may include blood tests, an ECG to check your heart, and imaging scans to map the tumour precisely. Your team will review your medical history and any medications you take.

Bowel preparation

Many patients are asked to empty their bowel before surgery. This usually involves a special laxative solution and a change to your diet in the day or two beforehand. Your team will give you clear instructions on what to do and when.

Talking through your questions

This is the time to raise any worries. Ask about the type of operation planned, whether a stoma is likely, how long you’ll be in hospital, and what recovery will involve. Understanding the plan helps you feel more in control.

Fasting before the operation

You’ll normally be asked to stop eating and drinking for a set number of hours before surgery. This keeps you safe during the anaesthetic.

What happens during the operation?

On the day, you’ll be taken to theatre and given a general anaesthetic, so you’ll be asleep and feel nothing throughout.

The surgeon then removes the affected part of the colon along with a margin of healthy tissue and nearby lymph nodes. If possible, the healthy ends are rejoined. If not, a stoma is created. In keyhole surgery, the whole procedure is done through small incisions with the help of a camera.

Most colon operations take between two and four hours, though complex cases can take longer. The removed tissue is sent to a laboratory, where it’s examined to confirm the stage of the cancer and check that all of it has been removed.

What happens after colon cancer surgery?

Recovery happens in stages, and your team will support you at each one.

In hospital

You’ll wake up in a recovery area and then move to a ward. Pain relief, fluids and sometimes a temporary drain or catheter are normal in the first days. Nurses will encourage you to move around gently and start sipping fluids, then eating, as your bowel wakes up.

Most patients stay in hospital for a few days to a week, though this varies with the type of surgery and how quickly you recover.

At home

Once home, you’ll need several weeks to regain your strength. Light activity, gentle walks and plenty of rest all help. Avoid heavy lifting until your surgeon says it’s safe. If you have a stoma, a stoma nurse will teach you how to care for it before you leave hospital.

Follow-up and further treatment

You’ll have follow-up appointments to check your healing and review the laboratory results. Depending on the stage of the cancer, your team may recommend chemotherapy after surgery to reduce the chance of it returning. Regular check-ups and scans help keep an eye on your long-term health.

Living well after surgery

Most people recover well from colon cancer surgery and return to the life they enjoy. Eating a balanced diet, staying active, and attending your follow-up appointments all support your recovery. Reach out to your care team whenever something feels off—no question is too small.

Surgery can feel like a daunting hurdle, but it’s a well-trodden path with a strong track record. Thousands of people go through it every year and come out the other side. Understanding each stage—preparation, operation and recovery—turns the unknown into something manageable.

If you’d like to explore treatment options or arrange a consultation with an experienced surgical team, get in touch with our patient support team. And do read the earlier posts in this series on symptoms, diagnosis and treatment options for a fuller picture of your journey.

Frequently asked questions

How long does colon cancer surgery take?

Most colon cancer operations take between two and four hours. Complex cases—such as those involving multiple tumours or a total colectomy—can take longer. Your surgeon will give you a clearer estimate based on your specific plan.

Will I need a stoma after colon cancer surgery?

Not always. Many patients have their bowel rejoined during surgery and never need a stoma. A stoma is more likely if the two ends of the bowel can’t be safely reconnected straight away, or if the rectum also needs removing. When a stoma is needed, it’s often temporary.

How long is recovery after colon cancer surgery?

Most patients stay in hospital for a few days to a week, then need several weeks at home to regain strength. Keyhole surgery usually means a faster recovery than open surgery. Your surgeon will advise when you can return to work and normal activity.

When is the whole colon removed instead of part of it?

A total colectomy is uncommon. It’s usually recommended when a patient has multiple tumours, or an underlying condition such as familial adenomatous polyposis (FAP) or ulcerative colitis that raises the risk of further cancers. In most cases, only the affected section of colon is removed.

Do I need chemotherapy after surgery?

It depends on the stage of your cancer and whether it has spread to the lymph nodes or beyond. Some patients need chemotherapy after surgery to lower the risk of the cancer returning, while others do not. Your team will discuss this once the laboratory results are back.