Bladder and bowel problems

Some types of cancer treatment can cause side effects that affect your bladder and bowel. There are things you can do to manage these.

Causes of bladder and bowel problems

Some types of cancer treatment can cause bladder and bowel side effects. These side effects are common after pelvic radiotherapy or treatment for bowel cancer. They may also be caused by the drugs you are taking as part of your treatment for cancer.

Bladder problems

Bladder problems might include:

  • passing urine (peeing) more often than usual
  • passing urine during the night
  • a burning feeling when you pass urine (similar to a urine infection)
  • a feeling that you are not able to wait when you need to pass urine
  • blood in your urine
  • leaking small amounts of urine (incontinence).

Contact the hospital straight away if:

  • your symptoms get worse
  • you have a high temperature
  • you feel you cannot pass urine.

Your healthcare team may ask you for a urine sample to check if you have an infection. An infection is a common cause of symptoms and is easy to treat. If the problems do not improve within a few weeks, they may arrange tests. Or they may get more advice for you from a continence specialist.

People often feel embarrassed talking about bladder problems. But if you tell your team, they can help, and it is usually possible to improve it.

Bowel problems

Bowel problems might include:

  • loose stools (poo) or diarrhoea
  • hard stools or constipation
  • needing to empty your bowel (poo) urgently
  • cramping pains in your tummy (abdomen) or back passage (rectum)
  • passing a lot of wind.

Tips for coping with bladder and bowel problems

There are some things you can do that may help with bladder and bowel problems:

  • If your urine is dark and concentrated, try to drink at least 2 to 3 litres (3½ to 5½ pints) of fluids a day.

    Darker urine can irritate the bladder and make symptoms worse. Drinking more makes your urine paler and less concentrated.

  • Try to drink more water and less drinks that may irritate the bladder and bowel.

    These include drinks containing caffeine, such as tea, coffee, drinking chocolate and cola. You should also try to drink less alcohol, fizzy drinks, acidic drinks (orange and grapefruit juice) and drinks with artificial sweeteners (diet or light drinks).

  • Try drinking cranberry juice to help reduce bladder symptoms – (but not if you are taking a drug called warfarin).

    You can also get cranberry capsules from your pharmacy.

  • If you smoke, try to stop.

    Smoking can make bladder and bowel side effects worse.

  • Look at our tips below for finding a toilet when you are out in public.

    It can help to plan ahead. There are also different resources available to help you.

If side effects do not get better, tell your specialist nurse or doctor.

Finding a toilet in a hurry

Bladder or bowel side effects may mean you need to go to the toilet more often. Or that you sometimes need to use the toilet urgently. Some people feel anxious about going out in public because of this.

Planning ahead so that you are prepared can help you feel more confident. We have more information about using public toilets.


Constipation means that you are not able to open your bowels (poo) as regularly as you normally do. It can become difficult or painful for you to poo. Some chemotherapy drugs, anti-sickness drugs and painkillers can cause constipation. It can also be caused by iron tablets or anti-diarrhoea drugs, such as loperamide.

Your doctor or specialist nurse can check if you are taking any drugs that can cause constipation. They may be able to change the dose or prescribe a different drug that may affect you less.

You may need to take medicines that help you poo (laxatives). Your doctor can give you more advice. They may give you one of the following treatments.

  • Soluble fibre supplements

    Soluble fibre supplements can be used to treat constipation. These include Fybogel® or Normacol®.

  • Suppositories

    You put these into your back passage or stoma. As they dissolve they release a lubricant. This encourages the bowel to empty. They usually take about 10 to 30 minutes to work. It may be easier to use them at a time when you are able to stay near a toilet for a while after inserting them. You may not need to use them every day.

  • Enemas

    These contain a small amount of gel or liquid that you squeeze into the lower bowel. This stimulates the bowel to empty.

Tips for coping with constipation

  • Eat plenty of fibre (roughage) each day

    Good sources of fibre include whole-wheat breakfast cereals and bread, brown rice, wholemeal pasta and fresh fruit and vegetables.

  • Drink plenty of fluids, at least 2 litres (3½ pints) a day

    This is particularly important if you increase the amount of fibre in your diet. This is because eating fibre without drinking enough fluids can make constipation worse.

  • Try a natural remedy for constipation

    These include prune juice, prunes, fig syrup and dried apricots.

  • Do gentle exercise

    Keep active. Gentle exercise, such as walking will help keep your bowels moving.

  • Speak to your doctor about your medicine dose

    If you are constipated because of the medicines you are taking, it may be possible to change the dose you take. You may need to take laxatives (medicines that help you poo) as well. Your doctor can give you more advice.

If you have bowel cancer, or you think your cancer treatment is causing constipation, ask your doctor or specialist nurse for advice.


Diarrhoea usually means that you have to open your bowels more often than you normally do. The bowel movements are also looser than normal.

Chemotherapyradiotherapytargeted therapies and surgery can all cause diarrhoea. Sometimes an infection or other medications can also cause diarrhoea, this includes antibiotics.

If your diarrhoea is caused by radiotherapy or chemotherapy, it is important to take the anti-diarrhoea medicines prescribed by your doctor. If you have diarrhoea after surgery for bowel cancer, talk to your doctor or specialist nurse before changing your diet.

Diarrhoea can be a temporary, mild side effect. But for some people, it can be severe and they will need to see a doctor to help manage it. Tell your doctor if you have diarrhoea or if it is getting worse. They can find out the cause and prescribe anti-diarrhoea medicines.

If you have more than 4 to 6 episodes of diarrhoea a day, contact the hospital on the telephone numbers you have been given and speak to a doctor or nurse.

Tips for coping with diarrhoea

  • Drink plenty of liquid (at least 2 litres or 3½ pints a day) to replace the fluid lost with the diarrhoea.
  • Avoid drinking alcohol and coffee.
  • Eat small, frequent meals made from light foods, for example white fish, poultry, well-cooked eggs, white bread, pasta or rice.
  • Eat your meals slowly.
  • Eat less fibre (for example cereals, raw fruits and vegetables) until the diarrhoea improves.
  • Avoid greasy, fatty foods such as chips and beef burgers, and spicy foods like chilli peppers.

Antibiotics can kill off the healthy bacteria normally found in the bowel. This can cause diarrhoea. The bacteria found in live yoghurt or yoghurt drinks may replace the healthy bacteria so may help ease diarrhoea caused by antibiotics. But you should avoid live yoghurt while you are having chemotherapy or if your immunity is low.


The amount of wind we produce depends on the way healthy bacteria and digestive enzymes in our bowel combine with the foods we eat.

Common causes of wind after cancer treatment may include:

  • pelvic radiotherapy (to the lower tummy area) can cause the pelvic floor muscles to become weaker
  • some types of bowel surgery
  • constipation
  • some types of medicines, such as Fybogel® and Lactulose®.

If you find wind difficult to cope with or if it becomes painful, tell your doctor or specialist nurse.

Tips for coping with wind

  • Eat and drink slowly. Take small mouthfuls and chew your food well.
  • Avoid food that you think gives you wind. Beans and pulses, pickles and fizzy drinks commonly cause problems.
  • A popular natural remedy is to drink two teaspoons of peppermint water dissolved in a small cup of hot water. You can sweeten this with sugar. Or you could try peppermint tea.
  • You could try taking charcoal tablets, which you can buy from the chemist. However, charcoal can affect other medicines you may be taking so always ask your doctor or pharmacist first.
  • Gentle exercise, especially walking, can improve wind.
  • Try to ensure you poo regularly – wind can be a sign of constipation.
  • Your GP can prescribe peppermint oil capsules that may help.
  • Use exercises to strengthen the muscles used for bowel control (pelvic floor exercises).

Date reviewed

Reviewed: 01 November 2020
Next review: 01 November 2023

This content is currently being reviewed. New information will be coming soon.

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