Mucositis is when your mouth or gut is sore and inflamed. It's a common side effect of chemotherapy and radiotherapy for cancer. It can be very unpleasant, but usually stops in a few weeks.

Tell your care team if you're having cancer treatment and get:

  • a sore mouth
  • mouth ulcers
  • difficulty swallowing, eating or talking
  • a dry mouth and lips
  • diarrhoea, bleeding from your bottom, or pain when pooing

These are symptoms of mucositis. They usually begin around 1 to 2 weeks after starting cancer treatment.

Treatments for mucositis

Mucositis should get better within a few weeks of finishing cancer treatment.

Your care team can offer treatments to ease it, such as:

  • mouthwashes that clean, numb and protect your mouth
  • painkillers
  • sprays or gels to keep your mouth moist (saliva substitutes)
  • medicines to stop diarrhoea or reduce soreness inside your bottom (rectum)

How you can help ease mucositis yourself

Keeping your mouth clean and making changes to your diet can help if you have mucositis.


  • brush your teeth with a soft toothbrush at least twice a day
  • floss once a day
  • rinse your mouth with warm water (or water mixed with salt or baking soda) several times a day – your care team can advise you how to do this
  • suck on crushed ice or ice lollies
  • eat soft, moist foods – try adding gravy or sauces to meals
  • drink plenty of water
  • chew sugar-free gum – this can help keep your mouth moist


  • use mouthwashes you can buy from shops – these can make mucositis worse
  • eat crunchy, rough or sharp foods like crisps
  • eat hot, spicy or salty foods
  • eat acidic foods like tomatoes, oranges or lemons
  • drink hot drinks (like tea and coffee), fizzy drinks or alcohol
  • smoke
  • take any medicines without speaking to a pharmacist, nurse or doctor first

Talking to others can help

You may also find it useful to chat to people in a similar situation or who have had cancer treatment before.

Ask your care team about support groups in your area.

You could also try an online forum like:

Page last reviewed: 23/11/2017
Next review due: 23/11/2020

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