What Is a Colectomy?

If you've been told you may need a colectomy, the questions tend to arrive in a rush. How much of the bowel comes out? Will I need a bag? When can I eat normally again? A colectomy is an operation to remove part — or, less often, all — of the colon, the long muscular tube that forms most of your large intestine. This guide walks through what to expect in the order you'll actually meet it: why the operation is suggested, what happens on the day, and how recovery usually unfolds.

Why your team may suggest taking out a section of colon

Surgeons don't remove bowel lightly. A colectomy is usually offered when a stretch of colon is diseased, damaged, or at serious risk, and leaving it in place would cause more harm than taking it out. The common reasons include a cancer or a large polyp that can't be removed through a scope, repeated attacks of diverticulitis that keep landing you in hospital, inflammatory bowel disease that no longer responds to medicines, a blockage, or a section of bowel that has lost its blood supply.

Often the path to that decision starts with a camera test. Our colonoscopy hub explains how the colon is examined from the inside, and our companion guide to what a colonoscopy involves covers that test itself — many colectomy patients first meet their surgeon after a colonoscopy finds something that needs an operation rather than a scope-based treatment.

How much is removed depends on where the problem sits. Removing the right side of the colon is called a right hemicolectomy, the left side a left hemicolectomy, and the lower S-shaped part a sigmoid colectomy. Occasionally the whole colon has to go — a total colectomy — but for most people it is one section, with the healthy ends joined back together.

The operation at the top of this page

The video above, "Laparoscopic Assisted Right Hemicolectomy", runs about eleven and a half minutes and follows the right-sided version of the operation done with keyhole surgery. In a laparoscopic — keyhole — approach, the surgeon works through several small incisions using a camera and long instruments, with one slightly larger incision used to remove the section of bowel. Not every colectomy can be done this way; some are done as open surgery through a single longer incision, and occasionally an operation that starts as keyhole is converted to open if that is the safer course once the surgeon can see inside. Your team will tell you which approach they plan and why.

Whichever route is used, the core steps are the same. You're asleep under a general anaesthetic. The surgeon frees the diseased section of colon from its attachments, divides the blood vessels that supply it, removes that section, and then — in most cases — joins the two healthy ends together. That join is called an anastomosis, and protecting it while it heals shapes much of the recovery that follows. The removed tissue is sent to the laboratory for examination, and those results often guide what happens next.

Our shorter companion video, "Laparoscopic Colectomy", gives a brief second look at the keyhole approach.

Before the day itself

Preparation usually starts a day or two ahead. Many teams ask you to follow a light or liquid diet for a short period and to take bowel preparation — strong laxative drinks that empty the colon — along with antibiotics in some centres. You'll be told when to stop eating and drinking before the anaesthetic, and you'll meet the anaesthetist as well as the surgical team. It's also the point where the possibility of a stoma is discussed (see the questions below), so do ask about it then rather than wondering in silence.

Waking up, and the first days afterwards

You'll wake in a recovery area with a drip in your arm and, often, a urinary catheter for the first day or so. Discomfort is expected and is managed with pain relief — being able to breathe deeply, cough, and move matters more than being completely pain-free, so tell the team if pain is stopping you doing those things.

Two things surprise people. First, how soon you're encouraged to get up: walking the ward from the first day or two is standard, because moving helps your bowel wake up and lowers the risk of chest problems and blood clots. Second, how the bowel restarts. It commonly goes quiet for a few days after handling, then announces its return with wind before stools follow. Drinks usually come first, then light food as your gut tolerates it. Most people stay in hospital for several days; exactly how long depends on the approach used, how your bowel behaves, and how you're managing at the bedside.

Going home, and settling into a new routine

At home, tiredness is normal for some weeks — this is major surgery, even through small incisions. You'll usually be advised not to lift anything heavy for a while and to build activity back up gradually. Eating tends to return to normal in stages; loose or more frequent stools are common early on, especially after a right-sided resection, and generally settle as the remaining bowel adapts.

Sometimes the bowel join needs protecting, or the ends can't safely be joined at all, and the surgeon brings the end of the bowel out through the abdominal wall as a stoma, with output collected in a bag. A stoma may be temporary — reversed once the join below has healed — or permanent, depending on the operation. Our guide to what a colostomy is explains that side of things in plain language. Either way, you'll be shown how everything works before you leave hospital, and you should leave with a follow-up plan and a clear sense of which symptoms — fever, worsening pain, vomiting, a wound that's becoming red or leaking, or no bowel output at all — mean you should contact the team straight away rather than waiting.

References & further reading

• MedlinePlus Medical Encyclopedia — Large bowel resection: https://medlineplus.gov/ency/article/002941.htm
• MedlinePlus — Ostomy: https://medlineplus.gov/ostomy.html
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — Ostomy Surgery of the Bowel: https://www.niddk.nih.gov/health-information/digestive-diseases/ostomy-surgery-bowel
• National Cancer Institute — Colon Cancer Treatment: https://www.cancer.gov/types/colorectal/patient/colon-treatment-pdq

Frequently Asked Questions

Will I definitely need a stoma bag after a colectomy?

No. In most colectomies the surgeon joins the two healthy ends of bowel back together and no stoma is needed. A stoma is created when joining isn't safe — for example in some emergency operations or very low resections — and it may be temporary, with a second operation later to reverse it. Your surgeon should discuss the likelihood in your case before the operation whenever it isn't an emergency.

What's the difference between a colectomy and a hemicolectomy?

Colectomy is the general term for removing part or all of the colon. A hemicolectomy removes roughly one side of it — right or left — and is the name used for the operation in the video at the top of this page. A sigmoid colectomy removes the lower S-shaped section, and a total colectomy removes the whole colon.

How long does recovery take?

Most people are in hospital for several days and feel notably better within a few weeks, but full recovery from major bowel surgery is usually measured in weeks rather than days, and open surgery tends to take longer than keyhole surgery. Your team will give you a personal estimate based on the operation you had and your general health.

Can I eat normally after part of my colon is removed?

Usually, yes, in time. The colon's main jobs are absorbing water and storing stool, and the remaining bowel adapts. Early on, stools are often looser or more frequent, and your team may suggest reintroducing foods gradually. Long-term restrictions are uncommon after a partial colectomy, but follow the advice you're given for your specific operation.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician-scientist.

Educational only — this article is general information about colectomy, not medical advice and not a diagnosis. Whether this treatment, or any treatment, is right for you is a matter for your own care team, who know your results and your history.