Sore mouth or gut (mucositis)

Mucositis is a condition which affects the gastrointestinal tract in your digestive system. The gastrointestinal, or GI, tract is a long tube that runs from your mouth to your anus. It includes your mouth, oesophagus (food pipe), stomach and bowels.

Mucositis causes the lining of your GI tract to become thin, making it sore and causing ulcers. This can happen after chemotherapy or radiotherapy. It’s painful, but it can be treated and gets better with time.

There are two types of mucositis. It’s possible to get both at the same time:

• Oral mucositis: This affects your mouth and tongue and can make talking, eating and swallowing difficult. It’s sometimes called stomatitis.
• GI mucositis: This affects your digestive system and often causes diarrhoea (frequent, watery poos).

Cancer treatments target cells that multiply quickly. This includes cancer cells, but also fast-growing healthy cells such as hair cells, skin cells and the cells in your GI tract. That’s why having chemotherapy or radiotherapy can make your hair fall out, increase your risk of sunburn and cause mouth or gut problems.

Mucositis happens when cancer treatments kill healthy cells in the GI tract. The lining of the GI tract gets thinner and becomes inflamed (sore and swollen).

The chance of getting oral or GI mucositis varies depending on the type of treatment you have and how intensive (concentrated) it is. Your genes and your general health also affect your likelihood of getting mucositis. Generally, mucositis affects:

• one or two out of five people (20–40%) who have standard chemotherapy
• four out of five people (80%) who have high-dose chemotherapy before a stem cell transplant, with or without total body irradiation (TBI).

Mucositis may be less severe if it’s picked up early, so do tell your healthcare team if you have symptoms. There are also treatments and self-care strategies which can reduce the risk of getting mucositis and help with the symptoms.