Sigmoid colectomy (removing the lower colon)

An operation to remove the sigmoid colon (the last bend of the large bowel before the rectum), usually for diverticular disease or a cancer, then join the bowel back together.

✓ Medically reviewed by a GMC-registered consultant · last reviewed September 2026 · next review September 2027 · how we review

In short

It removes the sigmoid colon, usually for diverticular disease or a cancer, and the bowel is then usually rejoined.
A stoma (bag) is sometimes needed — temporary or, less often, permanent — and the chance of this should be discussed beforehand.
It is major surgery: recovery often takes 6–8 weeks or more, and bowel habit can change for a time afterwards.
The most serious specific risk is the bowel join leaking (anastomotic leak); choose a team that does this regularly and explains your personal risk.

A plain-English summary. The detail — including risks and recovery — is below.

At a glance

TypeMajor bowel operation

AnaestheticGeneral anaesthetic

How long it takesAbout 2–4 hours

Hospital stayUsually a few days to over a week

Time off workOften 6–8 weeks, sometimes longer

When you'll see resultsBowel settles over weeks to months; final result depends on the reason for surgery

On the NHS?Commonly done on the NHS, often as cancer or diverticular-disease treatment

A general guide. Your surgeon will give you advice for your situation.

Best fit

Removes the diseased section of bowel causing repeated infection, bleeding or blockage

Pause if

Diverticular disease that is mild or settling and could be managed without surgery.

Main recovery point

You recover on the ward, often encouraged to sip fluids, eat lightly and get out of bed early. Pain is controlled with regular medicines. A thin tube may...

Good aftercare

An enhanced-recovery plan with clear advice on eating, moving, pain relief and return to activity.

First 24–72 hours

You recover on the ward, often encouraged to sip fluids, eat lightly and get out of bed early. Pain is controlled...

Days 3–7 (in hospital)

The bowel gradually wakes up; passing wind and then opening your bowels (or the stoma starting to work) are good...

Weeks 1–3 at home

Energy slowly returns. Walk little and often, avoid heavy lifting and build activity gradually. Bowel habit is...

Weeks 3–6

Most people feel steadily stronger and many return to lighter work. Open or emergency surgery, or a physical job...

Medical line illustration of lower gi colonoscopy for Sigmoid colectomy (removing the lower colon). — Illustration only - not a diagnosis, medical advice or a promise of result. Your anatomy and treatment plan may differ. Vuemedics does not publish before-and-after photos.

What is a sigmoid colectomy?

The sigmoid colon is the S-shaped last part of the large bowel, sitting on the left side just before the rectum. A sigmoid colectomy removes this section, usually because it is affected by repeated or complicated diverticular disease (small pouches in the bowel wall that become inflamed or perforate) or by a cancer or large polyp.

After the diseased part is removed, the surgeon usually joins the two cut ends of bowel back together. This join is called an anastomosis. Sometimes, if the bowel is very inflamed, infected or the join is risky, the surgeon brings the bowel out to the skin as a stoma (a bag) instead — either for a while or, occasionally, permanently. Your surgeon should explain in advance how likely a stoma is for you.

The operation can often be done by keyhole (laparoscopic) surgery through small cuts, which usually means less pain and a faster recovery. Sometimes open surgery through one larger cut is safer or necessary, and a planned keyhole operation can be switched to open during surgery as a safety decision.

If the operation is for cancer, surgery is one part of treatment planned by a multidisciplinary team (MDT). Removing the cancer does not on its own guarantee a cure, and some people also need other treatments and long-term follow-up.

Types & techniques

There isn't one single operation. The right approach depends on you — which is something to discuss with your surgeon.

Laparoscopic (keyhole) sigmoid colectomy

The usual planned approach where suitable: a few small cuts, a camera and instruments. Often means less pain, a shorter hospital stay and a quicker recovery than open surgery.

Open sigmoid colectomy

One larger cut in the tummy, used when keyhole is not safe or possible — for example with severe inflammation, scarring from previous surgery, or in an emergency.

Resection with primary anastomosis

The diseased bowel is removed and the two ends are joined straight away. The most common plan for planned (elective) surgery in people who are well enough.

Hartmann's procedure (with end colostomy)

The diseased bowel is removed but the ends are not joined; the bowel is brought out as a colostomy and the lower end is closed off. Used mainly in emergencies or when a join would be too risky. The stoma may sometimes be reversed later by a second operation.

Resection with a temporary stoma

The bowel is joined, but a temporary stoma is also made higher up to protect the join while it heals. It is usually reversed by a smaller operation weeks or months later.

Keyhole vs open surgery

Keyhole	Open
A few small cuts	One larger cut
Usually less pain	Usually more pain
Often shorter hospital stay	Often longer hospital stay
Faster recovery for many	Slower recovery
Usual first choice when safe	Used when keyhole is not safe

Keyhole is preferred where suitable, but open surgery is chosen when it is safer — for example with severe inflammation, scarring or an emergency. A keyhole operation may be converted to open during surgery for safety; this is a careful decision, not a failure.

Preparing for your surgery

See the operating surgeon to confirm why the operation is advised and whether it is for diverticular disease, a cancer or another reason.
Have any recommended tests, such as a colonoscopy, CT scan or staging scans for cancer, before surgery.
Ask the surgeon how likely a stoma is for you, and meet the stoma nurse to mark a site and learn the basics, even if a stoma is only a possibility.
Tell the team about all medicines, especially blood thinners, and about diabetes, heart or chest problems.
Stop smoking beforehand if you can, as smoking raises the risk of chest, wound and healing problems.
Follow the unit's enhanced-recovery advice, which may include bowel preparation, special drinks and getting as fit as possible beforehand.
Arrange time off work (often 6–8 weeks), a lift home and help at home for the first week or two.

What happens

The operation is done under general anaesthetic, so you are asleep, and usually takes about 2 to 4 hours. In keyhole surgery the surgeon makes a few small cuts, gently inflates the tummy with gas to see clearly, frees the sigmoid colon and removes it with its blood supply and nearby lymph nodes (especially important in cancer surgery).

The two ends of bowel are usually joined back together with staples or stitches. If the bowel is very inflamed, infected or the join is felt to be risky, the surgeon may instead bring the bowel out as a stoma, or make a temporary protecting stoma above the join. If the anatomy is unclear or there is heavy inflammation, a keyhole operation may be safely switched to open surgery.

Afterwards you wake in the recovery area and then go to a ward. Many units use an enhanced-recovery programme to help you eat, drink and move sooner. The removed bowel is sent to the laboratory, and for cancer the results help plan any further treatment and are discussed by the MDT.

Is this operation right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

May not be suitable if…

Diverticular disease that is mild or settling and could be managed without surgery.
You are not fit enough for a general anaesthetic and major surgery until other health problems are managed.
An emergency where a different operation (such as Hartmann's procedure with a stoma) is safer than rejoining the bowel.
A cancer where the multidisciplinary team advises a different operation or other treatment first.

Delay surgery if…

You have an active infection or are acutely unwell and need stabilising first.
Your blood-thinning medicine cannot yet be safely managed around surgery.
Poorly controlled diabetes, heart or lung disease that needs optimising.
Important results or staging scans are not yet available to plan the right operation.
You have not yet met the stoma nurse or had a site marked when a stoma is possible.

Alternatives to discuss

Medical and lifestyle management (fibre, fluids, treating flare-ups) for many people with diverticular disease.
Watchful waiting and reviewing symptoms before deciding on surgery for non-urgent cases.
Endoscopic removal of some early cancers or large polyps, where suitable, instead of bowel resection.
A different operation such as Hartmann's procedure in an emergency or high-risk situation.
The NHS pathway rather than private care where speed is not the priority.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

What matters most to me?

Think about symptoms, daily life, work, caring responsibilities, sport, fertility, travel, appearance and anxiety — the right choice depends on your priorities, not just the medical facts.

What are all my options?

Ask about waiting, monitoring, medicines, rehabilitation, a smaller or larger procedure, a different test, NHS referral, or a second opinion where that would help.

What would make me pause?

Active infection, pregnancy, unstable medical problems, smoking, medicines that increase bleeding, poor support at home, or feeling pressured are all reasons to slow down and get tailored advice.

What happens if I do nothing today?

For some problems, waiting is safe; for others, delay can make treatment harder. A good consultation should explain the trade-off in plain English.

Anaesthetic choices

The safest option depends on the operation, your health, the facility and your surgeon/anaesthetist. Ask what is planned and why.

General anaesthetic

You are fully asleep. This is standard for both keyhole and open sigmoid colectomy.

Epidural or spinal for pain relief

A regional injection in the back is sometimes used alongside the general anaesthetic to help control pain after open surgery.

Benefits

Removes the diseased section of bowel causing repeated infection, bleeding or blockage
For cancer, removes the tumour and nearby lymph nodes as part of treatment
Can stop repeated, severe attacks of diverticulitis in selected people
Keyhole surgery, where suitable, usually means smaller scars and a quicker recovery
Most people who have the bowel rejoined avoid a permanent stoma

Risks & complications

More common

Pain, bruising and tiredness while you recover
A slow, sluggish bowel for a few days after surgery (it takes time to wake up)
Changes in bowel habit, such as looser or more frequent stools, that often settle over weeks to months
Wound discomfort and a small risk of wound infection

Less common

Bleeding, sometimes needing a transfusion
Needing to convert from keyhole to open surgery
Needing a stoma when one was not planned
Chest infection or a urine infection after surgery
Blood clots in the legs or lungs

Rare but serious

Leak from the bowel join (anastomotic leak), which is serious and may need further surgery and a stoma
Injury to nearby organs such as the ureter (tube from the kidney), bladder, spleen or small bowel
A collection of infection (abscess) inside the tummy needing drainage
A hernia at a wound site later on
Serious problems related to the general anaesthetic, including very rarely a risk to life

The most serious specific risk is a leak from the bowel join (anastomotic leak), which can make you very unwell and sometimes needs more surgery and a stoma. Emergency operations carry higher risks than planned ones. Ask your surgeon how often they do this operation, your personal chance of needing a stoma (temporary or permanent), and what would happen if the join leaked.

Published figures to discuss

Risk depends heavily on whether surgery is planned or an emergency, the reason for surgery, the degree of inflammation, and your general health. The figures below are cautious ranges from surgical studies and audits, not guarantees for any one person. Emergency operations carry higher complication and stoma rates than planned ones.

Figure	Reported range	How to interpret it	Source / confidence
Anastomotic leak (leak from the bowel join)	Reported around 5% across colorectal joins in general, varying by site and circumstances	Serious; more likely in emergency, low or high-risk joins. May need further surgery and a stoma. Source: NHS patient information and surgical literature.	NHS — Diverticular disease and diverticulitisnhs.ukPublished figure
Death within 90 days of a leak needing reintervention	Higher than without a leak; one large study reported around 3.9% mortality with leakage versus 1.5% without	Risk rose mainly when a further operation was needed for the leak. Source: population-based cohort study (PMC6354192).	Sigmoid resection with primary anastomosis vs Hartmann's for perforated diverticulitis — meta-analysis (PMC)ncbi.nlm.nih.govPublished figure
Conversion from keyhole to open surgery	Varies widely by case mix; more likely with severe inflammation, obesity or previous surgery	A safety decision, not a failure. Exact rates differ between units and patient groups.	Sigmoid resection with primary anastomosis vs Hartmann's for perforated diverticulitis — meta-analysis (PMC)ncbi.nlm.nih.govSource-linked context
Needing a stoma	Varies by indication; common in emergency surgery and uncommon in straightforward planned surgery	May be temporary or permanent. Your personal chance should be discussed beforehand.	Guide sourcesClinical context

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

Recovery — what to expect, and when

Sigmoid colectomy is major bowel surgery. Many people are in hospital for several days and take around 6–8 weeks to feel back to normal, sometimes longer after open or emergency surgery. Bowel habit often takes weeks to months to settle.

First 24–72 hours

You recover on the ward, often encouraged to sip fluids, eat lightly and get out of bed early. Pain is controlled with regular medicines. A thin tube may drain urine at first.

Days 3–7 (in hospital)

The bowel gradually wakes up; passing wind and then opening your bowels (or the stoma starting to work) are good signs. Many people go home in this window once eating, drinking and moving comfortably.

Weeks 1–3 at home

Energy slowly returns. Walk little and often, avoid heavy lifting and build activity gradually. Bowel habit is often unpredictable at this stage.

Weeks 3–6

Most people feel steadily stronger and many return to lighter work. Open or emergency surgery, or a physical job, usually takes longer.

Beyond 6–8 weeks

Recovery is usually well advanced. Bowel habit continues to settle, though some changes can last. Cancer follow-up and any further treatment continue as planned.

What's normal — and not a worry

Tiredness for several weeks that gradually improves
A bloated, gurgly tummy in the first days as the bowel restarts
Looser, more frequent or unpredictable bowel motions that usually settle over weeks to months
Soreness around the wounds and some bruising
Reduced appetite at first, improving as you recover

Aftercare

Take painkillers as advised and keep moving little and often to lower clot and chest-infection risk.
Build up activity gradually and avoid heavy lifting until your surgeon says it is safe.
Eat regular, balanced meals; you may be advised on fibre and fluids while your bowel settles.
Keep wounds clean and dry and follow advice on showering and dressings.
If you have a stoma, use the stoma nurse's support and keep their contact details to hand.
Do not drive until you can brake hard comfortably, are off strong painkillers and your insurer agrees.
Watch for warning signs such as severe tummy pain, fever or a swollen, painful tummy.
Keep follow-up appointments and ask for your laboratory (pathology) results to be explained.

Before-surgery checklist

Painkillers in stock with a plan for taking them regularly
Help arranged at home for the first week or two
Loose, comfortable clothing and easy, balanced meals ready
Stoma supplies and the stoma nurse's number, if you may have a stoma
Time off work booked (often 6–8 weeks)
Knowledge of warning signs (severe pain, fever, no wind or stool)
The ward or clinic's contact number saved for problems

Scars and how they heal

Keyhole surgery leaves a few small scars plus one slightly larger cut where the bowel is removed, often near the navel or low down. Open surgery leaves a longer scar down the middle or across the tummy. If you have a stoma, there is also a small round site on the abdomen. Scars are pink and firm at first and usually fade over months.

⚠ Get urgent help if…

Severe or worsening tummy pain, or a hard, swollen, tender tummy
A high temperature, shivering or feeling very unwell (possible infection or leak)
Not passing any wind or stool with vomiting (possible blockage)
Spreading redness, heat, swelling or discharge from a wound
Heavy bleeding from the back passage, wound or stoma
A swollen, hot or painful calf, or breathlessness or chest pain (possible clot — call 999)
A stoma that stops working, turns dark/dusky, or pulls in or bulges suddenly

Who to contact: your surgeon or clinic first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your surgeon gives you.

Results & realistic expectations

If the operation is for diverticular disease, removing the diseased sigmoid colon usually stops the repeated attacks, although bowel habit can change and a small number of people have ongoing symptoms.

If it is for cancer, the aim is to remove the tumour completely with a clear margin and nearby lymph nodes. The laboratory results, discussed by the MDT, show how far the cancer had spread and whether other treatment (such as chemotherapy) is advised. Surgery cannot promise a cure, which is why follow-up and any further treatment matter. A good team is honest about what the operation can and cannot achieve in your case.

How long it lasts

For diverticular disease, removing the sigmoid colon deals with that section for good, though pouches can occasionally affect other parts of the bowel and symptoms do not always disappear completely. For cancer, long-term outcome depends on the stage of the cancer and your overall health; follow-up scans and blood tests over several years aim to pick up any return early. Bowel habit usually settles over time but may not be exactly as it was before.

Combining with other procedures

Sigmoid colectomy is sometimes combined with other steps during the same operation, such as making or reversing a stoma, or dealing with related problems found at surgery. For cancer, it is part of a wider plan that may include scans, chemotherapy and long-term follow-up rather than a one-off treatment. You should not feel pressured into unrelated add-on procedures.

Follow-up & long-term care

You will usually be reviewed after surgery to check healing and explain the laboratory (pathology) results. For cancer, NICE advises regular follow-up in the first years with blood tests (including the CEA tumour marker) and CT scans to look for any return, plus a plan for future bowel checks (colonoscopy). If you have a stoma, you will have ongoing stoma-nurse support and a plan for whether and when it might be reversed. You should always be told who to contact for problems.

Attend all follow-up appointments, scans and bowel checks, especially after cancer surgery.
If you have a stoma, keep up stoma care and reviews, and discuss reversal timing if relevant.
Build back up to normal activity and lifting gradually over weeks.
Eat a balanced diet and adjust fibre and fluids on advice while your bowel settles.
Report any new change in bowel habit, bleeding, weight loss or tummy pain promptly.
Stop smoking and keep to a healthy weight to support healing and lower future risk.

Revision and secondary surgery reality

An anastomotic leak may need a further operation, drainage or a stoma.
A temporary stoma usually needs a second, smaller operation to reverse it, which carries its own risks and is not always possible.
A Hartmann's stoma can sometimes be reversed later, but reversal is a significant operation and may not be offered to everyone.
A hernia at a wound site may need repair in the future.

Ask your surgeon for their own revision rate, what counts as a revision, and what is included in the written aftercare policy.

What good aftercare looks like

An enhanced-recovery plan with clear advice on eating, moving, pain relief and return to activity.
A named contact and out-of-hours number, with clear warning signs for leak, infection or blockage.
Explanation of the laboratory (pathology) results and, for cancer, the MDT plan and follow-up schedule.
Stoma-nurse support and a clear plan for reversal where a stoma is temporary.
A clear route back to the team for persistent pain, bleeding or changes in bowel habit.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

Keyhole versus open approach and the complexity of your case
Surgeon's and anaesthetist's fees
Theatre/facility time and length of hospital stay
Whether the operation is planned or urgent
Whether a stoma is formed and the stoma supplies and nursing support needed
Pre-operative tests and staging scans, and any further treatment for cancer
Follow-up appointments, scans and the policy if a complication occurs

Make sure your written quote includes

The surgeon's fee and the anaesthetist's fee
The hospital/facility and theatre fee, and the expected length of stay
Whether stoma formation, supplies and stoma-nurse support are covered if needed
Pre-operative tests, scans and explanation of laboratory (pathology) results
Follow-up appointments and any cancer surveillance scans/colonoscopy
The cancellation policy
What happens, and who pays, if there is a complication such as a leak needing more surgery or a longer stay

On the NHS? Sigmoid colectomy is widely available on the NHS, often as treatment for bowel cancer or complicated diverticular disease; private care may be chosen for speed or choice of surgeon, but urgent and cancer surgery is normally arranged promptly on the NHS.

You're entitled to your total cost in writing — including aftercare and any revision — before you decide.

Choosing a surgeon safely

Check your surgeon is on the GMC Specialist Register for this area.
Make sure they practise at a CQC-registered location, and look for membership of bodies like BAAPS or BAPRAS.
You're entitled to a two-stage consent process with time to reflect (a cooling-off period). The surgeon who will operate must consent you — not a salesperson.
Be wary of pressure: time-limited offers, discounts or deposits taken before you've had time to think are red flags, not bargains.
You're entitled to your total cost in writing — including aftercare and any revision — before you decide.

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Questions to ask your medical professional

Take this to your consultation. A good surgeon will welcome every one of these.

Is this operation for diverticular disease, a cancer or another reason, and what are my alternatives?
How likely am I to need a stoma, and would it be temporary or permanent?
How often do you do this operation, and is it likely to be keyhole or open for me?
What is my personal risk of an anastomotic leak, and what would happen if it occurred?
If it is for cancer, what further treatment and follow-up might I need afterwards?
Who do I contact if I get severe pain, fever or other problems after I go home?
Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
Will you be the surgeon who carries out my operation, and who looks after me afterwards?
What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
What does a realistic result look like — and what can this operation not achieve?
What are my options, including waiting, doing nothing for now, or choosing a different approach?
Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Frequently asked questions

Will I need a stoma (bag)?

Often not, if the bowel can be safely rejoined, but it depends on why you are having surgery and how the operation goes. A stoma may be temporary to protect a join, or occasionally permanent. Ask your surgeon for your personal chance of needing one, and meet the stoma nurse beforehand.

Can this be done on the NHS?

Yes. Sigmoid colectomy is commonly done on the NHS, especially as treatment for cancer or complicated diverticular disease. Private care may be chosen for speed or choice of surgeon, but urgent and cancer surgery is normally arranged quickly on the NHS.

How long is the recovery?

Most people are in hospital for several days and take around 6–8 weeks to feel back to normal, sometimes longer after open or emergency surgery or a physical job. Bowel habit can take weeks to months to settle.

What is an anastomotic leak?

It is a leak from the join made between the two ends of bowel. It is uncommon but serious, can make you very unwell, and may need further surgery and a stoma. Recognising it early matters, which is why you are watched closely and given warning signs.

Will my bowel ever be normal again?

Many people return to a fairly normal pattern, but bowel habit can change after losing part of the colon — for example looser or more frequent motions — and may not be exactly as before. This often improves over months. Ongoing problems should be reviewed.

Is keyhole always possible?

No. Keyhole surgery is preferred where suitable, but open surgery is sometimes safer — for example with severe inflammation, scarring or in an emergency. A keyhole operation may also be switched to open during surgery as a safety decision.

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How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: NICE NG151 — Colorectal cancer (recommendations) Bowel Cancer UK — Surgery Sigmoid resection with primary anastomosis vs Hartmann's for perforated diverticulitis — meta-analysis (PMC) Population-based study: mortality after anastomotic leak following rectal resection (PMC) Current indications for the Hartmann procedure (ScienceDirect) NHS — Diverticular disease and diverticulitis

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.