If you’re having radiation to the pelvic area, the radiation therapists may advise you to drink fluids before each radiation treatment so you have a full bladder. This will expand your bladder and push the bowel higher up into the abdomen, away from the radiation.
Even with precautions, radiation therapy can irritate the lining of the bowel or stomach and affect the way the bowel works. These changes are usually temporary, but for some people they are permanent and can have a major impact on quality of life. It is important to talk to your treatment team if you are finding bowel issues difficult to manage.
Learn more about:
Diarrhoea
This is when you have frequent loose, watery bowel motions. Diarrhoea can also cause abdominal cramping, wind and pain. After radiation therapy, you will need to go to the toilet more urgently and more often. Having diarrhoea can be tiring, so rest as much as possible and ask others for help. Diarrhoea can take some weeks to settle down after treatment has finished.
Radiation proctitis
Radiation therapy to the pelvic area can damage the lining of the rectum, causing inflammation and swelling known as radiation proctitis. Symptoms may include blood and mucus in bowel motions; discomfort opening the bowels; or the need to empty the bowels often, perhaps with little result. Ask your treatment team about your risk of developing radiation proctitis. Radiation proctitis is usually short term but may be ongoing in a small number of people. If you have any ongoing problems, they may refer you to a gastroenterologist.
How to manage bowel changes
- Ask your doctor about suitable medicines for diarrhoea. Take as directed.
- Check with your treatment team before taking any over-the-counter or home remedies, as taking them with anti-diarrhoea medicines may cause unwanted effects.
- Drink peppermint or chamomile tea to reduce abdominal or wind pain.
- Eat or drink as well as you can to give your body the nutrients it needs.
- Do some gentle exercise, such as walking, to encourage healthy bowel movements. Check with your doctor about the amount and type of exercise that is right for you.
- Avoid alcohol and cut down on coffee, cola and other drinks that contain caffeine.
- Drink plenty of clear liquids when you first notice symptoms of diarrhoea. This helps to avoid dehydration and replaces fluids lost through diarrhoea. Try apple juice, weak tea, clear broth, sports drinks and electrolyte-replacing fluids. It may also be worth trying a lactose-free milk.
- Choose plain foods that are low in insoluble fibre (e.g. bananas, mashed potato, apple sauce, white rice or pasta, white bread, steamed white fish or chicken). Talk to your dietitian about what else you can eat.
- If you have diarrhoea, avoid high-fibre, fatty or fried foods; pulses; garlic and onion; and rich sauces and gravies, as these can make diarrhoea worse.
- Contact your treatment team immediately if there is blood in your bowel motions or if you have more than 5–6 bowel movements in 24 hours.
I had diarrhoea for a few weeks but it improved with medication.
Emma
More resources
Prof June Corry, Radiation Oncologist, GenesisCare, St Vincent’s Hospital, VIC; Prof Bryan Burmeister, Senior Radiation Oncologist, GenesisCare Fraser Coast, Hervey Bay Hospital, and The University of Queensland, QLD; Sandra Donaldson, 13 11 20 Consultant, Cancer Council WA; Jane Freeman, Accredited Practising Dietitian (Cancer specialist), Canutrition, NSW; Sinead Hanley, Consumer; David Jolly, Senior Medical Physicist, Icon Cancer Centre Richmond, VIC; Christine Kitto, Consumer; A/Prof Grace Kong, Nuclear Medicine Physician, Peter MacCallum Cancer Centre, VIC; A/Prof Sasha Senthi, Radiation Oncologist, The Alfred Hospital and Monash University, VIC; John Spurr, Consumer; Chris Twyford, Clinical Nurse Consultant, Radiation Oncology, Cancer Rapid Assessment Unit and Outpatients, Canberra Hospital, ACT; Gabrielle Vigar, Nurse Unit Manager, Radiation Oncology/Cancer Outpatients, Cancer Program, Royal Adelaide Hospital, SA.
View the Cancer Council NSW editorial policy.
Need to talk?
Support services
Coping with cancer?
Ask a health professional or someone who’s been there, or find a support group or forum
Need legal and financial assistance?
Pro bono legal and financial matters, no interest loans or help with small business
Cancer information
Nutrition and cancer
Many people have problems eating well during and after cancer treatment. This may be caused by the cancer or caused by the cancer treatments.
Relaxation and meditation
Learn how relaxation and mediation can help you both during and after cancer treatment, or listen to our relaxation and meditation audio tracks