Stomach or pelvic radiotherapy side effects: diarrhoea

This page tells you about diarrhoea and bowel changes due to radiotherapy treatment to your stomach or abdomen. There is information about

Diarrhoea due to abdominal radiotherapy
Treating diarrhoea
Needing to go to the toilet often

It is quite common to have diarrhoea during or after radiotherapy treatment to your stomach or abdomen. You may also have stomach cramps and wind. The diarrhoea usually starts gradually a few days after starting the radiotherapy. It can gradually get worse as the treatment goes on. Once the treatment ends the diarrhoea normally goes away gradually over a couple of weeks. But for some people it may continue for some weeks after your treatment. You may also notice some blood in your bowel movements. Let your doctor know if you have any bleeding. There is a trial looking at whether whether diets high or low in fibre are better for people having radiotherapy.

It is unpleasant to have diarrhoea and it can also make you feel weak and tired, so it is important to rest if you need to. Let your radiotherapist know if the diarrhoea is not starting to improve by a few weeks after your treatment has finished. If it continues, your doctor will need to refer you to a doctor who specialises in bowel problems after radiotherapy (a specialist gastroenterologist).

If you have diarrhoea, let your doctor, specialist nurse or radiographer know. There are several things that can help you.

Anti diarrhoea drugs, which your doctor prescribes
Anti spasm medicines from your doctor
Changing your diet may help – you can speak to a dietician at the hospital
Drinking lots of fluid – this is important, as you can easily get dehydrated

Radiotherapy to the large bowel can make you feel that you need to have your bowels open. This is called urgency or tenesmus. The feeling can be controlled with steroid suppositories or ointments, which also contain an anaesthetic.

You may find that you need to have your bowels open very often. You may also have to go several times before you feel the bowel is empty. Anti diarrhoea medicines can help. Doing regular pelvic floor exercises can also help. You can practice holding on to your stool to build up the amount the bowel can hold.

A physiotherapist or community continence adviser can give you advice and information about dealing with diarrhoea or other bowel problems. You can get details of your nearest continence clinic or adviser from the Bladder and Bowel Foundation.

'Just can’t wait' card

You can get a card if you want to go to the toilet more often, or feel that you can’t wait when you do want to go. You can show the card to staff in shops or pubs etc. It allows you to use their toilets, without them asking awkward questions. You can get the cards from Disability Rights UK or the Bladder and Bowel Foundation. They also have a map of all the public toilets in the UK.