What can happen?

Radiotherapy for prostate cancer (external beam radiotherapy and brachytherapy) can cause bowel problems for some men. Radiation can cause the lining of the bowel to become inflamed (proctitis) which then leads to symptoms such as:

  • loose and watery bowel movements (diarrhoea)
  • passing more wind than usual
  • needing to go to the toilet more often, or having to rush to the toilet
  • feeling an urge to have a bowel movement, but then not being able to go
  • a feeling that your bowels haven’t emptied properly
  •  pain in the stomach area (abdomen) or back passage
  • bleeding from the back passage – this is rare.

Some men find that changes to their bowel habits settle down a few weeks after finishing treatment. For others, the changes last longer. Some men get bowel problems months or years after treatment.

What can help?

Tell your GP, doctor, nurse or radiographer about any changes in your bowel habits. They can give advice and support to help manage them. There are medicines available to help with symptoms and control diarrhoea.

Your local continence services can assess your bowel problems and offer advice about treatments. The continence service provides care and advice for people with bladder or bowel problems and is usually run by specialist nurses. Ask your GP to refer you.

If you have long term bowel problems, ask to be referred to a bowel specialist (gastroenterologist). You may have a further test to check for any damage to the bowel.

How can I manage bowel problems myself?

Living with bowel problems can be distressing, and for a lot of men it's not an easy thing to talk about. But remember that doctors and nurses often help men with these issues. They're used to discussing the problem and finding ways to deal with it.

You may find it helpful to plan ahead and find out where toilets are before you go out, and carry absorbent pads.

If you are having problems with diarrhoea, eating less fibre for a short time may help. Low fibre foods include white rice, pasta and bread, potatoes (without the skins), cornmeal, eggs and lean white meat. Speak to your doctor, nurse or radiographer before changing your diet.

Foods such as beans and pulses, cruciferous vegetables (for example, cabbage, broccoli and cauliflower), fizzy drinks and beer can all cause wind and bloating so you may want to avoid these. Chewing your food slowly can also help. 

Bowel problems and anal sex

If you’re gay, bisexual or a man who has sex with men, and are the receptive partner (‘bottom’) during anal sex, then bowel problems after radiotherapy may be a particular issue. Read our information for gay and bisexual men.

Macmillan Cancer Support and the Bladder and Bowel Foundation produce detailed information about coping with bowel problems.