Page last updated: April 2025
The information on this webpage was adapted from Understanding Bowel Cancer - A guide for people with cancer, their families and friends (2025 edition). This webpage was last updated in April 2025.
Expert content reviewers:
This information was developed based on Australian and international clinical practice guidelines, and with the help of a range of health professionals and people affected by bowel cancer:
- Prof Alexander Heriot, Colorectal Surgeon and Director Cancer Surgery, Peter MacCallum Cancer Centre, Director, Lower GI Tumour Stream, Victorian Comprehensive Cancer Centre, VIC
- Dr Cameron Bell, Gastroenterologist, Royal North Shore Hospital, NSW
- Graham Borgas, Consumer
- Prof Michael Bourke, Director of Gastrointestinal Endoscopy, Westmead Hospital, The University of Sydney, NSW
- Laura Carman, 13 11 20 Consultant, Cancer Council Victoria, VIC
- Amanda Connolly, Specialist Bowel Care Nurse, Icon Cancer Centre Windsor Gardens, SA
- A/Prof Melissa Eastgate, Operations Director, Cancer Care Services, Royal Brisbane and Women’s Hospital, QLD
- Anne Marie Lyons, Stomal Therapy Nurse, Concord Repatriation General Hospital and NSW Stoma Ltd, NSW
- Lisa Nicholson, Manager Bowel Care Services, Bowel Cancer Australia, NSW
- Stefanie Simnadis, Clinical Dietitian, St John of God Subiaco Hospital, WA
- Rafi Sharif, Consumer
- Dr Kirsten van Gysen, Radiation Oncologist, The Nepean Cancer and Wellness Centre, NSW
- Sarah Williams, Clinical Nurse Consultant, Lower GI, Peter MacCallum Cancer Centre, VIC
Treatment for bowel cancer can affect how your bowel and digestion work. Some people may also find that some foods cause discomfort.
These changes can be difficult to adjust to. They usually improve over time, but issues may be ongoing and require specialised help.
If you experience problems, talk to your GP, specialist doctor, specialist nurse or dietitian. To find an accredited practising dietitian, visit Dietitians Australia's “find a dietitian” search tool.
Surgery for rectal cancer can lead to symptoms such as faecal incontinence, constipation or frequent bowel movements. This is known as low anterior resection syndrome (LARS), and it can last for months or years.
If you have ongoing bowel effects after rectal surgery, talk to your surgeon. Ways to improve bowel function may include changing what you eat, taking medicines and having physiotherapy.
Your guide to best cancer care
A lot can happen in a hurry when you’re diagnosed with cancer.
The guide to best cancer care for bowel cancer can help you make sense of what should happen. It will help you with what questions to ask your health professionals to make sure you receive the best care at every step.
Read the guide
Incontinence
Incontinence is when you can’t control your bowel or bladder.
Faecal incontinence
After surgery or radiation therapy, the movement of waste through the large bowel can become faster. You may feel that you can’t wait when you need to go to the toilet (urgency), you need to go more often, or you have less control over bowel movements.
Bowel surgery or radiation therapy may weaken the anus, making it difficult to hold on when you feel the need to empty your bowels, particularly if you have loose bowel movements (diarrhoea).
Urinary incontinence
This is when urine (wee or pee) leaks from your bladder without you being able to control it.
Bladder control may change after surgery or radiation therapy. For example, radiation therapy can irritate the lining of your bladder, because the bladder is located near the large bowel.
Some people find they need to urinate more often, need to go in a hurry or don’t fully empty the bladder. While you may feel embarrassed if you have bowel or bladder changes, there are ways to manage the symptoms.
Incontinence usually improves in a few months, but sometimes takes years. Talk to your treatment team about whether any bowel or bladder changes are likely to be permanent.
Ways to manage incontinence
- Talk to your surgeon or GP about available treatments. They may refer you to a continence nurse or physiotherapist, who can suggest exercises to strengthen your pelvic floor muscles.
- Call the National Continence Helpline on 1800 33 00 66 to talk to a continence nurse about continence aids, if needed, or visit Continence Health Australia.
- Find out the location of toilets near where you are. Visit the National Public Toilet Map or download the app to your smartphone.
- The Australian Government’s Improving Bowel Function After Bowel Surgery booklet has helpful tips about managing bowel problems.
- Bowel Cancer Australia has Bowel Care Nurses and a nutritionist specially trained to help manage and improve bowel dysfunction from LARS or bowel cancer.
Radiation proctitis
Radiation to the pelvic area can affect the lining of the rectum, causing inflammation and swelling (known as radiation proctitis).
This can lead to a range of side effects including diarrhoea and bleeding from the rectum, the need to empty the bowels urgently, and loss of control over the bowels (faecal incontinence).
These side effects may appear shortly after radiation therapy for rectal cancer, but are generally not an ongoing problem because the rectum is then removed during surgery.
Your treatment team will talk to you about the risk of developing radiation proctitis and ways to cope with bowel changes.
Diarrhoea
Diarrhoea is the frequent passing of loose, watery faeces (stools or poo). It can also cause abdominal cramping, wind and pain. Different types of treatment can cause diarrhoea:
- Surgery – If you have had part of your bowel removed, your bowel movements may be looser than you were used to. This is because the bowel absorbs water to form faeces. With a shorter bowel, the faeces don’t form as solidly as before. This may be ongoing, but there are many ways of managing diarrhoea.
- Radiation therapy – Diarrhoea is a common side effect of radiation therapy. It can take some weeks to settle down after treatment has finished. For a small number of people, diarrhoea is ongoing.
- Drug therapies – Chemotherapy, immunotherapy and targeted therapy drugs can cause diarrhoea and nausea. These side effects will go away after treatment and you can gradually return to a normal diet.
How to manage diarrhoea
- Eat small frequent meals instead of three big ones. Try eating every two hours.
- Low-fibre foods may be easier to digest. Examples include bananas, white rice, white pasta, white bread, potatoes, white fish and steamed chicken without the skin.
- Limit foods that increase bowel activity, e.g. caffeine; alcohol; spicy, fatty or oily foods; high-sugar fluids such as juice and soft/fizzy drink; artificial sweeteners.
- Raw fruit and vegetables, wholegrain breads and cereals, or legumes (e.g. lentils, chickpeas) may make diarrhoea worse. If they do, you may want to cut back on these foods for a few days.
- Lactose in dairy foods may make diarrhoea worse. Try low-lactose or soy-based products instead.
- Talk to your treatment team about ways to control diarrhoea, such as using over-the-counter medicines and changing what you eat.
- Watch for warning signs of dehydration. These include a dry mouth, dark yellow urine, dizziness and confusion. If dehydration is left untreated, it can be dangerous.
- Drink plenty of water (about six glasses a day) to avoid becoming dehydrated. Consider having an oral rehydration solution, such as Hydralyte or Gastrolyte.
- If your anus becomes sore, clean the area with warm water and a soft cloth or soft/water wipes or anal cleansing wipes (e.g. Rectogesic). Ask your treatment team to recommend a cream. Taking a soothing bath may also help.
- Having diarrhoea can make you feel tired. Try to rest as much as possible and ask family or friends for help.
- Ask for a referral to a dietitian or physiotherapist who looks after bowel issues. If diarrhoea continues for a few days, see a doctor.
“Three months after the ileostomy, I went in for the reversal surgery. You have to stay in hospital until you pass wind, which took six days. Passing wind will never lose its amusement.” Richard
Wind (flatulence)
Many people who have treatment for bowel cancer find that it gives them wind (gas or farting). This especially happens after you have had surgery. However, it is usually temporary and improves over time.
Working out what foods cause wind and what you can eat without side effects may help – although foods can still affect people differently.
Tips to manage wind
- Try chewing charcoal tablets, eating natural yoghurt and drinking peppermint tea.
- Cut your food into small, bite-sized pieces.
- Chew your food slowly and thoroughly.
- When you have a drink, take small sips and don’t use a straw.
- Talk to your doctor about what types of light exercise you can do to relieve bloating and wind.
- Foods such as eggs, legumes (e.g. lentils and chickpeas), fizzy drinks, and sugar-free foods may increase gas. If they do, you may find it helpful to limit these foods.
- Try keeping a food and symptom diary to help identify foods that cause wind.
- Ask your doctor if there are any medicines that may be helpful to you.
“When I first got put back together after the ileostomy, processed food really messed with me. The more processed it is, the slower my body deals with it. Some of the things I loved – pizza, processed meat, bread, red meat and potato – play with me. The greener the better – salads, fruit, fish, chicken really make me feel sensational.” Richard
Eating after treatment
Immediately after treatment – particularly surgery – you may be on a modified diet.
What you are able to eat might depend on the type of surgery you’ve had, how much of your bowel was removed and whether you have a stoma.
During and after treatment, you may find that certain foods upset your bowel and cause diarrhoea or wind.
Your health care team may suggest foods to avoid, but as foods can affect people differently, you will need to experiment to work out which foods cause problems for you.
It is better to limit – not exclude – these foods in your diet, as you may find that what you can handle improves over time.
Keeping a diary of what you eat can help. Make a note of the foods that cause constipation, diarrhoea or wind.
Your ability to handle different foods usually gets better with time but can take many months. When returning to your usual diet, introduce one food at a time.
If something causes a problem, try it again in a few weeks to see if your response has improved. Share this information with the health care team as it can help them figure out how to manage any issues.
Learn more about nutrition
Follow-up appointments
After treatment ends, you will have regular appointments to monitor your health, manage any long-term side effects and check that the cancer hasn’t come back or spread.
You will usually have a physical examination and you may have blood tests (including checking CEA levels), scans and colonoscopies.
You will usually have a follow-up colonoscopy a year after the colonoscopy that showed bowel cancer. However, this may be sooner if only part of the bowel was seen during the last colonoscopy.
Check-ups may become less frequent if you have no further problems. Between follow-up appointments, let your doctor know immediately of any symptoms or health problems. Don’t wait for your next appointment.
When a follow-up appointment or test is approaching, many people find that they think more about the cancer and may feel anxious. Talk to your treatment team or call Cancer Council 13 11 20 if you are finding it hard to manage this anxiety.
What if bowel cancer returns?
For some people, bowel cancer does come back after treatment, called a recurrence. Regular check-ups are important so if cancer comes back, it can be found early.
If the recurrence is only in the bowel and nearby lymph nodes, you may be able to have surgery to remove the cancer.
If bowel cancer has spread beyond the bowel (advanced or metastatic bowel cancer), you may be offered treatment, such as surgery, chemotherapy, targeted therapy, immunotherapy or radiation therapy.
These treatments may remove the cancer, help control its growth and relieve symptoms. If your bowel becomes blocked, you will need urgent treatment.