Key points about diarrhoea during cancer treatment
- diarrhoea is a common side effect of some cancer treatments.
- it can be caused by chemotherapy, infections, or food intolerance
- your child may need extra fluids and gentle foods to stay hydrated and comfortable
Causes of diarrhoea during cancer treatment
Diarrhoea can happen for several reasons.
Chemotherapy
Some medicines affect the lining of the gut - from the mouth right through to the bottom.
Infection
Tamariki (children) with low immunity are more at risk of viral infections like gastroenteritis. Your child is more at risk of this if they have low immunity.
Food intolerances
These may be temporary (due to gut damage from treatment) or pre-existing food intolerances.
Unsafe food
Some foods carry a higher risk of infection, especially for tamariki with low immunity.
Managing diarrhoea at home
Diarrhoea can cause your child to lose fluid quickly.
Offer extra fluids to help prevent dehydration:
- water
- diluted fruit juice
- coconut water or Hydralyte
Offer gentle foods
Give small, light meals more often than usual.
Suitable meals include:
- white bread
- rice
- pasta
- mashed potato
- pureed apple
- fish
- chicken
- low fibre cereals like cornflakes, Ricies and Coco-Pops
Avoid foods with seeds, pips, skins or coarse stalks until diarrhoea settles.
Food safety tips
If your child has low immunity (neutropenia), they are more vulnerable to infections. To keep food safe:
- wash your hands before preparing food
- use clean knives, chopping boards and benchtops when preparing food
- store cooked food above raw food in the fridge and keep it covered
- cook and reheat food until it is hot all the way through, especially when using a microwave oven
- check the use-by date on packaged foods
- wash fruit and vegetables under running water
Foods to avoid with diarrhoea or low immunity
Avoid giving your child:
- raw or undercooked seafood or eggs
- chilled or pre-cooked seafood products such as prawns, mussels, fish
- pre-cooked meat products such as pate, pre-cooked chicken and ham
- raw seafood and raw fish
- shop-prepared salads and coleslaws
- unpasteurised milk or milk products such as cheese made with unpasteurised milk - read the label for this information
Eating out can be risky - choose food that's cooked fresh while you wait. Avoid takeaway chicken.
See more information about food safety for people with low immunity.
When to call the hospital
Let your healthcare team know if:
- your child has ongoing diarrhoea
- you're worried about dehydration or food intake
- you're unsure what foods or fluids are safe
Acknowledgements
All the pages in the childhood cancer section of this website have been written by health professionals who work in the field of paediatric oncology. They have been reviewed by the members of the National Child Cancer Network (NZ). Medical information is authorised by the National Child Cancer Network Clinical Leader.
