Bowel cancer

Treatment for early bowel cancer

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Treatment options by type | Preparing for treatment | Surgery | Radiation therapy | Chemotherapy | Key points about treating early bowel cancer 


Colon cancer and rectal cancer are treated differently. Your health care team will recommend treatment based on what will give you the best outcome, where the cancer is in the bowel, whether and how the cancer has spread, your general health, and your preferences.

The treatment options you are offered will depend on the guidelines for best practice in treating bowel cancer. You may be offered a combination of surgery, chemotherapy, radiation therapy and chemoradiation. This page covers treatment for stage 1 to 3 bowel cancer. 


Cancer care pathways

For an overview of what to expect during all stages of your cancer care, from diagnosis to treatment and beyond, read or download the Guide to Best Cancer Care  for bowel cancer. This resource is also available in Arabic, Chinese, Greek, Hindi, Italian, Tagalog and Vietnamese – see details on the site.

Treatment options by type of bowel cancer

Colon cancer

  • Surgery is the main treatment for early and locally advanced colon cancer
  • If the cancer has spread to the lymph nodes, you may have chemotherapy after surgery, which is called adjuvant chemotherapy
  • Radiation therapy is not used for early colon cancer.

Rectal cancer

  • Surgery is the main treatment for early rectal cancer
  • If the cancer has spread beyond the rectal wall and/or into nearby lymph nodes, before surgery you will have chemotherapy or radiation therapy combined with chemotherapy (chemoradiation)
  • After surgery you may have further chemotherapy or radiation therapy. Trials are looking at other combinations of chemotherapy and radiation therapy.

Preparing for treatment

Managing anaemia

Many people with bowel cancer have anaemia or low iron levels. You may be given iron as tablets or injections to increase your iron levels and blood count (total number of white blood cells, red blood cells and platelets) before starting treatment.

Improve diet and nutrition

People with bowel cancer often lose weight and may become malnourished. A dietitian can suggest ways to change your diet to limit weight loss, reduce blockages and make having bowel movements easier. This will help improve your strength and lead to better treatment outcomes. 

Give up smoking

If you are a smoker, you will be encouraged to stop smoking before surgery. If you continue to smoke, you may not respond as well to treatment, and smoking may make any side effects you experience worse. For support, call the Quitline on 13 7848.


The type of surgery you have will depend on the location of the cancer in the bowel and your preferences. The aim of surgery is to remove as much of the cancer as possible and nearby lymph nodes.

How the surgery is done

There are two ways to perform surgery for bowel cancer. Each method has advantages in particular situations – your doctor will advise which method is most suitable for you.

Keyhole surgery

Also called minimally invasive or laparoscopic surgery, this method involves several small cuts (incisions) in the abdomen. A thin tube (laparoscope) is passed through one of the cuts. The laparoscope has a light and camera. Long, thin instruments are inserted through other small cuts to remove the section of bowel with the cancer. Keyhole surgery usually means less pain and scarring, a shorter hospital stay and faster recovery.

Open surgery

This is usually done with one long cut (incision) down the middle of your abdomen. Open surgery usually means a larger wound, slower recovery and a longer hospital stay. Open surgery is a well-established technique and widely available.

Surgery for cancer in the colon

The most common type of surgery for colon cancer is a colectomy (removal of a part of the bowel). Lymph nodes near the colon and some normal bowel around the cancer will also be removed.

The surgeon usually cuts the bowel on either side of the cancer (with a small border of healthy tissue called the margin) and then joins the two ends of the bowel back together. This join is called an anastomosis.

Sometimes one end of the bowel is brought through an opening made in your abdomen and stitched onto the skin. This procedure is called a colostomy (if made from the large bowel) or ileostomy (if made from the small bowel). The opening – called a stoma – allows faeces to be collected in a bag. The stoma is usually temporary, and the operation is reversed later. In some cases, the stoma is permanent. Improved surgical techniques now mean fewer people need a permanent stoma.

After surgery, you will have a scar. Most people who have open surgery have a scar from above their navel (bellybutton) to their pubic area.

Types of colectomies 

There are different types of colectomies depending on which part of the colon is removed. The surgery may be done as keyhole or open surgery. 

Types of colectomies

Surgery for cancer in the rectum

There are different types of operations for cancer in the rectum. The type of operation you have depends on where the cancer is located, whether the bowel can be rejoined, and where in the rectum the join can be made. The surgery may be performed using an open or keyhole approach.

There are two common types of operation:

  • Anterior resection – This is the most common operation. It may include creating a temporary stoma, which will be reversed later. 
  • Abdominoperineal resection – This procedure may be recommended if the cancer is near the anal sphincter muscles or if it is too low to be removed without causing incontinence (loss of control over bowel movements). After an abdominoperineal resection, you will need a permanent stoma (colostomy).

Types of resections

  • High anterior resection – The surgeon removes the lower left part of the colon and the upper part of the rectum. Nearby lymph nodes and surrounding fatty tissue are also removed. The lower end of your bowel is rejoined to the top of the rectum.
  • Abdominoperineal resection or excision (APR or APE) – The sigmoid colon, the entire rectum and the anus are removed. Your surgeon uses the descending colon to create a permanent stoma (known as a colostomy) for faeces to leave the body. The anal area will be stitched up and permanently closed.
  • Ultra-low anterior resection – The lower left part of the colon and the entire rectum are removed, along with nearby lymph nodes and fatty tissue. The end of the bowel is joined to the lowest part of the rectum, just above the anus. In some cases, the surgeon creates another way for waste to leave the body.
  • Colonic J-pouch – An internal pouch is made from the lining of the large bowel. This J-pouch will be connected to the anus and work as a rectum. You may have a temporary ileostomy (a stoma from the small bowel), which will be reversed once the J-pouch heals.

Other types of surgery

Local excision

People who have very early-stage rectal cancer or are not fit for a major operation may have a local excision. The surgeon inserts an instrument into the anus to remove the cancer from the lining of the rectum, along with a margin of healthy tissue, without cutting into the abdomen. Methods include transanal excision (TAE), transanal endoscopic microsurgery (TEMS) and transanal minimally invasive surgery (TAMIS).

If there are two cancers

In a small number of people, two separate cancers may be found in the large bowel at the same time. The cancers may be discovered through diagnostic tests or during surgery. In this case, there are several options for surgery:

  • remove two sections of the bowel
  • remove one larger section of the bowel, which includes both areas with cancer
  • remove the entire colon and rectum (proctocolectomy) to prevent any chance of another cancer forming.

The type of surgery your doctor recommends depends on several factors including your age, the location of the tumours in the bowel, genetic and other risk factors, and your preferences.

Surgery for a blocked bowel (bowel obstruction)

Sometimes as the bowel cancer grows it completely blocks the bowel. This is called bowel obstruction. Waste matter cannot pass through the blocked bowel easily, and may cause:

  • bloating and abdominal pain
  • constipation
  • nausea and vomiting.

Sometimes the obstruction is found and cleared during the surgery to remove the cancer. In other cases, the bowel obstruction will mean you have to have emergency surgery to clear the blockage.

It may be possible to rejoin the bowel during the surgery, but some people may need a stoma. Sometimes a stoma is made "upstream" from the obstruction to relieve the blockage and to allow time for staging scans of the cancer or chemoradiation before surgery, to make sure the cancer is removed completely.

Not everyone with a blockage will want to have surgery or be fit enough to have it. To help keep the bowel open so that stools can pass through again, your surgeon may be able to insert a small hollow tube (stent) inside the colon. A stent may also help manage the blockage until you are well enough to have an operation. Your surgeon will use a colonoscope to find the blockage and place the stent.

If you are unable to have surgery or a stent, you may be given medicine to help control the symptoms of a bowel obstruction. A dietitian can also suggest ways to add more fibre to your diet to help food or waste pass through the blockage or stent more easily.

Risks of bowel surgery

Your surgeon will talk to you about the risks and complications of bowel surgery. As with any major operation, bowel surgery has risks. Complications may include infection, bleeding, blood clots, damage to nearby organs, or leaking from the joins between the removed parts of the bowel. You will be carefully monitored for any side effects afterwards.

Most hospitals in Australia have programs to reduce the stress of surgery and improve your recovery. These are called enhanced recovery after surgery (ERAS) or fast-track surgical (FTS) programs, and they encourage you to play an active part in your care through pre-admission counselling, and education about pain control, diet and exercise so you know what to expect each day after the surgery.

What to expect after surgery

This is a general overview of what to expect. Your recovery time after the operation will depend on your age, whether you had keyhole or open surgery and your general health. 

Recovery time

  • You will probably be in hospital for 4–7 days, but it can take 2–3 months to fully recover.
  • While you are in hospital you will have to wear compression stockings to keep the blood flowing in your legs.
  • You will also be given a daily injection of a blood thinner to reduce the risk of developing blood clots.
  • Some people also wear a special cuff that applies intermittent pressure to the legs.
  • Some people may have to wear the stockings and have the injections for a couple of weeks after the surgery.

Pain relief

  • You will have some pain and discomfort for several days after surgery, but you will be given pain-relieving medicines to manage this.
  • Pain relief may be given in various ways:
    • by an injection near your spinal column (epidural or spinal anaesthetic)
    • through a drip which you can control with a button (PCA – patient controlled analgesia)
    • as pills or tablets
    • through little tubes giving local anaesthetic near your wound (TAP block catheters).
  • Let your doctor or nurse know if you are in pain so they can adjust the medicines to make you as comfortable as possible. Do not wait until the pain is severe.

Drips and tubes

  • You will be given fluids through a drip (also called an intravenous or IV infusion) until you can start eating and drinking again. You may need a drip for a few days.
  • You may also have other tubes – from your bladder to drain urine (catheter) or from your abdomen to drain fluid from around the surgical area.
  • In most centres, you will be given water to drink a few hours after the surgery and you will usually start on solid foods the day after the surgery (or even on the day of the surgery if you feel well). You may also be given nutritional supplements to drink.
  • In some centres, you will not have anything to eat or drink for several days after the surgery.


  • Your health care team will encourage you to walk the day after the surgery.
  • You will need to avoid heavy lifting (more than 3–4 kg) for about 4–6 weeks.
  • A physiotherapist will teach you breathing or coughing exercises to help keep your lungs clear. This will reduce the risk of getting a chest infection.
  • Gentle exercise has been shown to help people manage some of the common side effects of treatment and speed up a return to usual activities.

Side effects of bowel surgery

Radiation therapy

Also known as radiotherapy, this uses a controlled dose of radiation, such as focused x-ray beams, to kill or damage cancer cells. The radiation treats only the area that the radiation is aimed at. This means there is less harm to the normal body tissue near the cancer.

Radiation therapy is often combined with chemotherapy (chemoradiation). This is because chemotherapy makes cancer cells more sensitive to radiation. See Understanding Radiation Therapy.

External beam radiation therapy is the most common type of radiation therapy for rectal cancer. Newer techniques deliver the dose to the affected area with little damage to surrounding tissue. This helps reduce the number of side effects from radiation therapy.

During treatment, you will lie on a treatment table under a machine called a linear accelerator. Each treatment takes only a few minutes, but a session may last 10–20 minutes because of the time it takes to set up the machine.

If radiation therapy is given with chemotherapy, you will have it once a day for 5–6 weeks, then there will be a gap of 6–12 weeks before surgery. This break allows the radiation therapy to have its full effect. If radiation therapy is given by itself, you will have a shorter course, usually for five days, then a shorter gap before surgery. 

When is radiation therapy given?

Radiation therapy may be recommended for rectal cancer but is not generally used to treat colon cancer.

  • Before surgery (neoadjuvant) – A short course of radiation therapy or a longer course of chemoradiation is used to shrink the tumour before surgery for rectal cancer. The aim is to make the cancer smaller, so it is easier for the surgeon to completely remove the tumour and reduce the risk of the cancer coming back.
  • After surgery (adjuvant) – Occasionally, if the rectal cancer is found to be more advanced than originally thought, radiation therapy may be used after surgery to destroy any remaining cancer cells. 

Side effects of radiation therapy

The side effects of radiation therapy vary. Most are temporary and disappear a few weeks or months after treatment. Radiation therapy for rectal cancer is usually given over the pelvic area, which can irritate the bowel and bladder.

Common side effects include feeling tired, needing to pass urine more often and burning when you pass urine (cystitis), redness and soreness in the treatment area, faecal urgency and incontinence, diarrhoea, constipation, mucus discharge or small amounts of bleeding from the anus. Radiation therapy can cause the skin or internal tissue to become less stretchy and harden (fibrosis). It can also affect fertility and sexual function.

People react to radiation therapy differently, so some people may have few side effects, while others have more. Your treatment team will give you advice about possible side effects and how to manage them.

Radiation proctitis

Radiation to the pelvic area can damage the lining of the rectum, causing inflammation and swelling (known as radiation proctitis). This can cause a range of symptoms including diarrhoea, the need to empty the bowels urgently and loss of control over the bowels (faecal incontinence).

When treating rectal cancer, these side effects may appear shortly after radiation therapy, but are generally not a problem long term because the rectum is removed during surgery. Your treatment team will talk to you about your risk of developing radiation proctitis. See also some ways to cope with bowel changes.

Effects on fertility and sexual function

Radiation therapy to the pelvis and rectum can affect your sexual function and ability to have children (fertility). See Fertility and Cancer and Sexuality, Intimacy and Cancer for more information.

For men

  • Radiation therapy can damage sperm or reduce sperm production. This may be temporary or permanent.
  • Most doctors suggest using contraception and not having unprotected sex during and for one month after radiation therapy treatment.
  • You will be able to store sperm at a hospital or fertility clinic before treatment starts. Talk to your doctor about this.
  • Because radiation therapy can damage blood vessels and nerves that produce erections, some men may have erection problems. Your doctor may prescribe medicine or refer you to a specialist clinic to manage this problem.

For women

  • Radiation therapy can cause the vagina to become shorter and narrower, making sexual intercourse painful. Your doctor may suggest using a vaginal dilator after treatment ends and the area has healed to help gradually widen the entrance and prevent the side walls sticking together. 
  • Talk to your doctor about creams and moisturisers to help with vaginal discomfort and dryness.
  • In some cases, radiation therapy can stop the ovaries producing female hormones. This can cause menopause and infertility.
  • Menopause can be managed by menopause hormone therapy (MHT, previously called hormone replacement therapy or HRT). After menopause you will not be able to conceive a child. 
  • Share your feelings about any fertility issues with your partner, a counsellor or a fertility specialist.


Chemotherapy uses drugs to kill or slow the growth of cancer cells while doing the least possible damage to healthy cells. 

You may have chemotherapy through a liquid drip into a vein (intravenously) or as tablets. It may also be given through a thin plastic tube called a central venous access device. Some people have chemotherapy at home through a portable bottle called an infusor pump. You will probably have chemotherapy as a course of several sessions (cycles) over 4 to 6 months. You’ll have regular scans to monitor your response to the chemotherapy and your medical oncologist will explain your treatment schedule.

If the cancer has spread outside the bowel to lymph nodes or to other organs, chemotherapy may be recommended:

Before surgery (neoadjuvant)

Some people with rectal cancer have chemotherapy before surgery to shrink the tumour and make it easier to remove. You are likely to have chemotherapy together with radiation therapy (chemoradiation) for rectal cancer.

After surgery (adjuvant)

Chemotherapy may be used after surgery for either colon or rectal cancer to kill any remaining cancer cells and reduce the chance of the cancer coming back. If your doctor recommends chemotherapy, you will probably start treatment as soon as your wounds have healed and you’ve recovered your strength, usually within 6 to 8 weeks.

On its own

If the cancer has spread to other organs, such as the liver or lungs, chemotherapy may be used either to shrink the tumours or to reduce symptoms and make you more comfortable.

Side effects of chemotherapy

People react to chemotherapy differently – some people have few side effects, while others have many. The side effects depend on the drugs used and the dose. Your medical oncologist or nurse will discuss the likely side effects with you, including how they can be prevented or controlled with medicine. It is uncommon to need a break or change in your treatment.

Common side effects include tiredness; feeling sick (nausea and vomiting); diarrhoea; mouth sores and ulcers; changes in appetite, taste and smell; sore hands and feet; and hair loss or thinning. You may also be more likely to catch infections.

Pins and needles, numbness, redness or swelling in the fingers and toes are more common if using the chemotherapy drug called oxaliplatin. Skin peeling and increased sensitivity to sunlight are more common if using the chemotherapy drug called fluorouracil (or 5-FU).

During chemotherapy, you will have a higher risk of getting an infection or bleeding. If you have a temperature over 38°C, contact your doctor or go to the emergency department. Tell your doctor if you feel more tired than usual, or if you bruise or bleed easily.

Keep a record of the doses and names of your chemotherapy drugs handy. This will save time if you become ill and need to visit the emergency department. See Understanding Chemotherapy.

Key points about treating early bowel cancer

Treatments for early colon cancer

  • The main treatment is surgery to remove part or all of the colon (colectomy)
  • There are different types of colectomies depending on where the cancer is located
  • If cancer has spread from the colon to nearby lymph nodes, you may have chemotherapy after surgery.

Treatments for early rectal cancer

  • The main treatment is surgery to remove all or part of the rectum (resection)
  • There are different types of resections depending on where the cancer is located
  • A local excision to remove the cancer may occasionally be used for very early-stage rectal cancer
  • If the cancer has spread to nearby tissue or lymph nodes, before the surgery you will usually have radiation therapy or chemoradiation.

How surgery is done

  • Surgery for bowel cancer may be done as keyhole surgery (several smaller cuts) using a tiny surgical instrument with a camera and light, or open surgery (one large cut)
  • During bowel surgery, the surgeon cuts the bowel on either side of the cancer and joins the two ends back together
  • If it is not possible to join the bowel back together or if the bowel needs time to heal, a diversion is created for faeces to come through a hole (stoma) in the abdominal wall.


Expert content reviewers:

A/Prof David A Clark, Colorectal Surgeon, Royal Brisbane and Women’s Hospital, and The University of Queensland, QLD, and The University of Sydney, NSW; A/Prof Siddhartha Baxi, Radiation Oncologist and Medical Director, GenesisCare Gold Coast, QLD; Dr Hooi Ee, Specialist Gastroenterologist and Head, Department of Gastroenterology, Sir Charles Gairdner Hospital, WA; Annie Harvey, Consumer; A/Prof Louise Nott, Medical Oncologist, Icon Cancer Centre, Hobart, TAS; Caley Schnaid, Accredited Practising Dietitian, GenesisCare, St Leonards and Frenchs Forest, NSW; Chris Sibthorpe, 13 11 20 Consultant, Cancer Council Queensland; Dr Alina Stoita, Gastroenterologist and Hepatologist, St Vincent’s Hospital Sydney, NSW; Catherine Trevaskis, Gastrointestinal Cancer Specialist Nurse, Canberra Hospital, ACT; Richard Vallance, Consumer.

Page last updated:

The information on this webpage was adapted from Understanding Bowel Cancer - A guide for people with cancer, their families and friends (January 2021). This webpage was last updated in March 2021. 

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