Living with cancer

Gastrointestinal side effects

Gastrointestinal side effect such as nausea (sickness) and vomiting, constipation and diarrhoea are common side effects of some cancer treatments but they are not inevitable It is important to let your healthcare team know if you experience any gastrointestinal side effects, so that they can be treated promptly and effectively. Everyone is different and it may take several different combinations of medications to find what works best for you.

Making changes to your diet and practising relaxation techniques an also help you to manage many gastrointestinal side effects.

You can be an active partner by keeping a note of your symptoms and anything that makes them better or worse

Nausea and vomiting

Nausea and vomiting are the side effects that most people associate with cancer treatment. They occur when a part of the brain called the vomiting centre is stimulated. Cancer treatments that are most likely to cause nausea and vomiting include specific chemotherapy drugs and radiotherapy to the brain or abdominal (tummy) area.

Things to do if you are suffering with nausea and vomiting

  • Take your anti-sickness medication as prescribed and tell your healthcare team if it is not working so you can try something different.
  • Take anti-sickness medication 30 minutes before you plan to eat.
  • Eat small light meals throughout the day especially around chemotherapy treatments.
  • Eat slowly and chew your food thoroughly to aid digestion.
  • Eat cool bland comfort foods at least until you see how you will feel eating.
  • Eat toast, crackers and cereal to help settle your stomach.
  • Drink liquids after meals ( not with meals) to avoid feeling full.
  • Try relaxation techniques and slow deep breathing when you feel sick.
  • Eat cold meals or food from the freezer that only needs heating up if the smell of cooking makes you feel sick.
  • If possible let someone else do the cooking.
  • Take foods containing ginger e.g. ginger tea or ginger biscuits.
  • Sip fizzy drinks.
  • Sip peppermint tea or chew mint.
  • Ask your healthcare team about using seabands.

Things to avoid if you are suffering with nausea and vomiting

  • Waiting until you feel sick before trying to take anti-sickness medication.
  • Smoky places or places with other strong smells.
  • Strong perfumes or after-shave.
  • Eating your favourite foods when you feel sick.
  • Eating or preparing food when you are feeling sick.
  • Drinking at the same time as eating.
  • Fried, sweet and/or spicy foods.
  • Orange or grapefruit juice which may irritate your stomach.


Difficulty having a bowel movement is common for people undergoing cancer treatment. Medications, surgery, inactivity and dietary changes are just a few of the things that can contribute to changes in normal bowel function. Normal bowel movements vary from person to person. If you can tell your healthcare team what is normal for you, it will help them to assess you and recommend the best treatment. If you have a colostomy or ileostomy you may need specific advice. Your healthcare team will be able to tell you what to expect and how to prevent or manage constipation.

Things to do if you are suffering from constipation

  • Take stool softeners and/or laxities as recommended by your health care team.
  • Ask you healthcare team whether fibre supplements may help.
  • Drink plenty of fluids, up to 8 glasses of water a day to help promote bowel function.
  • Have plenty of fibre (roughage) in your diet e.g. wholewheat breakfast cereals, wholemeal bread and pasta, brown rice, fruit and vegetables with skins on.
  • Take syrup of figs, prunes or prune juice.
  • Take light exercise e.g. walking.
  • Have meals at the same time each day if possible to encourage regular bowel habit.

Things to avoid if you are suffering with constipation

  • Over the counter medications unless recommended by your healthcare team.
  • Taking laxatives if you have constipation and vomiting – you should contact your healthcare team for advice.


Diarrhoea is the passing of three or more watery bowel movements a day and can be severe side effects of some cancer treatments. It is very important to gain control of diarrhoea quickly because nutrients and body fluids can easily be lost in a short period of time. I diarrhoea is a likely side effect of your treatment plan your healthcare team will advise you on how to manage it and when to call them if it becomes severe. If you experience severe diarrhoea you may need to be admitted to hospital for intravenous ( drip) fluids.

If your diarrhoea is caused by radiotherapy treatment, changing your diet is unlikely to help and you will need anti-diarrhoea medication. If you have a colostomy or ileostomy you may also need specific advice. Your healthcare team will be able to tell you what to expect and recommend medications you can take to prevent or to manage diarrhoea.

Things to do if you are suffering with diarrhoea

  • Take anti-diarrhoea medication as recommended by your healthcare team.
  • Keep track of your bowel movements. If the number increases to six or more a day you should contact your healthcare team.
  • Ask your healthcare team about taking rehydration drinks or over the counter diarrhoea treatments.
  • Drink plenty of fluids e.g. water, herbal teas, clear soups, non fizzy drinks, electrolyte replacement drinks.
  • Eat six small meals a day.
  • Eat a good bland diet, such as the BRAT diet. BRAT stands for Bananas, rice apple sauce and toast.
  • Eat foods that tend to make stools firmer e.g. rice, pasta, potatoes without the skin, white bread, bananas.
  • Wash your hands before and after going to the toilet, wipe the rectal area (around your back passage) with a baby wipe or mild soap and water, pat dry carefully and apply a soothing ointment like zinc oxide or petroleum jelly.
  • Have warm baths to sooth the rectal area.
  • Use cotton underwear.
  • Be prepared when you go out. Know where toilets are and take spare underwear, pads and a plastic bag just in case.
  • Ask your healthcare team about mattress protectors and commodes if you are worried about getting to the toilet at night.

Things to avoid if you are suffering from diarrhoea

  • Over the counter anti-diarrhoea medications unless recommended by your healthcare team.
  • Greasy, fired, fatty, spicy and pickled foods.
  • Foods high in acid like tomatoes and citrus fruit.
  • Alcohol, orange juice and foods containing caffeine e.g. coffee, chocolate.
  • Eating foods high in fibre.
  • Dairy foods such as milk, yoghurt, cheese butter and cream.
  • Rubbing the rectal area after your bath or shower.
  • Tight underwear or trousers.
  • Long journeys where access to toilets may be difficult.