Colectomy (large bowel resection): an OR 101 guide
Reviewed by Rodnie Oro, cath lab charge nurse · Last reviewed: October 2026 · Education only, not medical advice
Colectomy in one minute
What it is: surgery to remove part of the large bowel (colon) and join the ends (anastomosis) or bring an end out as a stoma.
Who it is for: people with bowel cancer, diverticular disease, inflammatory bowel disease or a blockage.
Main risks: leak from the join, infection, bleeding, slow bowel recovery, blood clots, needing a stoma.
Usually: under general anaesthetic, 2–5 hours, about 3–7 days in hospital.
On this page: What is a colectomy? · Who is it for? · When is it done? · Step by step · Recovery · Risks · Kit list · First time in theatre? · FAQ
What is a colectomy?
The colon (large bowel) absorbs water and carries waste to the rectum. A colectomy removes the diseased part, with its blood supply and lymph nodes when treating cancer:
- Right hemicolectomy: the right side of the colon
- Left or sigmoid colectomy: the left side or the sigmoid colon
- Subtotal or total colectomy: most or all of the colon
The ends are joined with staples or stitches, or one end is brought out to the skin as a stoma (colostomy or ileostomy), sometimes temporarily. Most planned operations are keyhole or robotic; emergencies are often open.
New to the acronyms? See the Cath Lab Abbreviations A–Z.
Who is it for?
It may be considered for people with:
- bowel cancer
- complicated diverticular disease
- ulcerative colitis or Crohn's disease not controlled by medicines
- a blocked, twisted or perforated bowel (emergency)
The decision is made by your surgical team, who will talk through the reasons, the alternatives and the risks with you.
When is it done?
Most operations are planned; some are urgent. Before it, you usually have:
- scans (CT) and a camera test of the bowel (colonoscopy)
- blood tests and an ECG
- bowel preparation and carbohydrate drinks, as per centre protocol (enhanced recovery)
- a stoma nurse visit and stoma site marking if a stoma is possible
- a review of your medicines, especially blood thinners, as per centre protocol
- a chance to ask questions and give consent
Step by step
1. Getting ready
Team brief and WHO checklist first. The anaesthetic team and ODP give a general anaesthetic and insert a breathing tube; antibiotics and blood-clot prevention are given as per centre protocol. The circulating practitioner checks positioning, pressure areas, the diathermy plate, warming, and that the camera stack and gas insufflator work. The scrub practitioner sets up the laparoscopic trolley and an open set in case of conversion, and does the first count. A urinary catheter is usually placed; leg positioning in stirrups may be needed for left-sided operations.
2. Access
Most often keyhole: four or five ports, sizes per device and operator, with a small extra cut to remove the bowel. For open surgery, a midline cut (laparotomy).
3. Removing the bowel
- A. Bowel mobilised. The colon is freed from its attachments.
- B. Blood supply divided. The blood vessels to that part are divided, with lymph nodes for cancer.
- C. Bowel removed. The bowel is divided with a stapler and removed through a small protected cut.
- D. Join or stoma. The ends are joined with staples or stitches, or a stoma is formed.
4. Finishing
The gas is let out, ports removed and the larger cuts closed (deep layer, per surgeon), then the skin with sutures or glue. Local anaesthetic is often injected into the wounds. Final counts are confirmed, specimens labelled and checked, and the patient goes to recovery with a full handover.
Recovery and aftercare
- First hours: in recovery, then a ward or day unit; pain relief and anti-sickness medicine as needed.
- Going home: often 3–7 days (enhanced recovery).
- Activity: walking early; avoid heavy lifting for about 6 weeks; ask your team.
- Eating: drinking and eating early, as advised.
- Stoma: if you have one, the stoma nurse teaches you how to care for it.
- Wounds: keep them clean and dry as advised; sutures or clips may need removing.
- Follow-up: clinic review or a phone call, as per centre protocol.
Call 999 if you have severe pain, heavy bleeding, breathlessness or collapse. Contact your team or GP if you have a fever, worsening tummy pain or swelling, vomiting, or a wound that becomes red, hot or leaky.
Risks and complications
Your team will explain the risks that apply to you. Possible problems include:
- a leak from the bowel join (anastomotic leak)
- wound or internal infection
- bleeding
- slow return of bowel function (ileus)
- injury to nearby organs (rare)
- needing a stoma, or a stoma that is permanent
- blood clots in the legs or lungs
- hernia at a wound later
Theatre kit list (printable)
Example kit list
Every theatre has its own protocol, and sizes and doses vary.
- laparoscopic stack: camera, scope, light source, gas insufflator and warmer
- ports, sizes per device and operator, and an entry needle or open-entry kit, per surgeon
- laparoscopic graspers, scissors, dissectors and suction-irrigation
- energy device, per surgeon
- linear and circular staplers and reloads, sizes per device and operator
- wound protector
- bowel clamps and an open bowel set
- stoma appliance if needed
- closure sutures and dressings
Procedural steps
- Team brief, WHO sign in; anaesthesia, lines, catheter; antibiotics as per centre protocol
- Positioning (supine or legs in stirrups); prep and drape; count
- Ports; inspection; mobilisation
- Vessels divided; bowel divided with staplers
- Specimen out via protected cut; anastomosis or stoma; leak test if done
- Closure; stoma appliance; counts; specimen check; sign out and handover
First time in theatre?
đź’ˇ First-time tip
- Know your role. Scrub, circulating, anaesthetic and ODP each have their own checks; ask at the team brief.
- Counts matter. Swabs, needles and instruments are counted before, during and at closure; speak up if one is missing.
- Specimens. Label every specimen with site and side, and check it with the scrub practitioner before it leaves theatre.
- Camera ready. Learn to white-balance the camera and warm the scope to stop fogging.
- Open set ready. An open tray stays available in case keyhole surgery has to convert to open.
FAQ
Will I need a stoma?
It depends on the operation. Your surgeon and stoma nurse will explain beforehand.
What is enhanced recovery?
A plan to help you recover faster: eating, drinking and walking early.
How long until I feel normal?
Many people take several weeks to a few months to feel fully recovered.
Related guides
Sources
All checked on 14 October 2026. Each page's own date is shown where it gives one.
- NHS. Bowel cancer: treatment. nhs.uk/conditions/bowel-cancer/treatment
- NICE. Colorectal cancer (NG151). nice.org.uk/guidance/ng151
- StatPearls (NCBI Bookshelf), search: colectomy. ncbi.nlm.nih.gov/books
- World Health Organization. Surgical Safety Checklist. who.int
Disclaimer
Education only. This page is for general education for healthcare students, theatre staff and curious readers. It isn't medical advice and doesn't replace advice from your own doctor, surgical team or local unit protocols. Equipment and medicines are described generically. No product or manufacturer is recommended. If you think someone is having a medical emergency, call 999.
Disclosure: I work in the medical device industry. This page is independent education and isn't sponsored or reviewed by any company.
All diagrams on this page are original illustrations created for rodnieoro.com.
