Diarrhoea & constipation

Living with and being treated for secondary breast cancer can cause a range of issues relating to the bowels, either increasing or reducing their frequency of motions. This may be a short-term symptom or side-effect or may be something you experience in the longer term.

In this section


Diarrhoea describes the need to open your bowels more times than is usual for you in one day and usually involves frequent, loose and watery stools. This can be caused by many things when living with and being treated for secondary breast cancer, including radiotherapy, chemotherapy, targeted (biological therapies) and antibiotics taken to treat infections. It can be a mild, short-term side-effect or may be more severe and ongoing. It can also cause you to have painful stomach cramps.

It is important to tell your doctor or nurse if you are struggling with diarrhoea, since it can cause you to become dehydrated (as you are losing lots of water when you go to the toilet) and unwell.

Please call your hospital to speak to your doctor or nurse if you are experiencing severe diarrhoea.

There are lots of things that you can do to help you manage with diarrhoea.

Tips for coping with diarrhoea

Eating and drinking

It is very important to drink plenty of fluids (2-3 litres of water a day) to replace lost fluids and prevent you from becoming dehydrated.

Try and avoid drinking caffeine and alcohol, since these can trigger or worsen diarrhoea.

Whilst fibre is an essential part of a healthy diet, high fibre foods (e.g. raw fruit & vegetables, including fruit juice) can worsen diarrhoea. Until the diarrhoea improves, try eating small, bland meals which are low in fibre e.g. white bread, pasta, cooked eggs, cooked vegetables (peeled & de-seeded), white fish and chicken.

It is also a good idea to avoid fatty, greasy or spicy foods.


If you are experiencing diarrhoea, it is important that you stop taking any laxative medications (e.g. Senna, Laxido, Dulcolax) which you may have previously been prescribed for constipation, as these can cause diarrhoea and cramping.  

A range of medications can be prescribed to treat diarrhoea. Some are known as anti-diarrhoeal drugs (e.g. Loperamide or ‘Immodium’) whilst others are known as anti-spasmodic drugs (e.g. hyoscine or ‘Buscopan’ and Mebeverine or ‘Colofac’). The anti-spasmodic drugs work by relaxing the muscle of the bowel to stop it from tightening and causing lots of bowel movements and cramping. If you have been prescribed these medications by your doctor, you should take the recommended dose as soon as you experience diarrhoea and continue to take them regularly as per the advice of your doctor or nurse. Be sure to read the treatment information on/in the packet of tablets. It is important that you do not exceed the maximum prescribed dose.

Please speak to your doctor or nurse before trying any new medications or if you are at all unsure about a medication you have been prescribed.

Looking after yourself

Having diarrhoea can be stressful and exhausting so it is important that you rest and look after yourself. Get plenty of sleep and try and relax in comfortable surroundings. Don’t be afraid to ask friends and family for help e.g. with cooking or childcare responsibilities.

Personal care is also very important when you are having diarrhoea, to prevent the skin around your anal area (bottom) from becoming sore or infected. Try using moist toilet paper or cotton wool to wipe yourself as this may be gentler. Wash with unscented or alcohol free soaps or washes and try and avoid sponges or flannels to prevent irritation. Carefully dry the area. You may find applying a barrier cream such as Sudocrem or Germolene to be soothing when sore. If you prefer more natural remedies, aloe vera gel can also be very soothing.

Being prepared

Coping with diarrhoea whilst managing your daily life can be stressful and challenging. Making sure you are prepared can help to ease your anxiety about being out and about. You may feel worried about not being close to a toilet or having an accident. This is completely natural and the following tips may help you to feel more in control and prepared:

  • Take an emergency ‘kit’ with you, including spare clothes and underwear, alcohol free moist wipes or baby wipes and soothing cream.
  • Try to avoid long car, bus or train journeys.
  • Find out where the nearest toilets are.

This can be a very distressing and embarrassing symptom to manage. However, there are lots of things to help you cope and your doctor and nurse will be extremely experienced (and not at all embarrassed!) in treating and managing diarrhoea.

Overflow diarrhoea

Overflow diarrhoea can happen when hard stool (poo) cannot be pushed out of the bowel (constipation) and watery stools leak from higher up in the bowel. The watery poo is able to pass around the blockage and can be mistaken for diarrhoea. In this case, you should not take anti-diarrhoeal or anti-spasmodic medications since this can make the blockage (constipation) worse.

If you have had severe constipation and then seem to develop diarrhoea, it is important that you speak to your doctor or nurse before taking any medications. 


Constipation describes not being able to open your bowels as regularly as is normal for you.

In secondary breast cancer, a range of treatments and medications can cause constipation, such as painkillers, chemotherapy drugs and anti-sickness medications. Changes to diet and physical activity can also lead to constipation.

It is very common for women to experience constipation at some point and it can be extremely uncomfortable, distressing and, at times, painful. There are lots of things that you can do to help relieve this so don’t struggle alone.

Tips for coping with constipation

Eating and drinking

There are lots of things you can eat and drink to help relieve constipation. However, it is important to speak to your doctor or nurse before changing your diet or trying anything new, since some forms of constipation are eased by a high fibre diet whilst others are better treated with a low fibre diet. Your doctor or nurse will be able to advise you on the dietary changes that will work best for you.

If a high fibre diet is advised, try including brown or wholegrain bread, rice and pasta and eating plenty of fresh fruit and vegetables (leaving the skin on where possible). Beans, pulses, lentils, oats and dried fruits are also great sources of fibre.

You may find that you experience some bloating and wind (flatulence) over the first few days of eating more fibre.

If a low fibre diet is advised to treat your constipation, try switching to white bread, rice and pasta and eating cooked, peeled and de-seeded vegetables. Fish, chicken, eggs and dairy foods can also be included.

It is very important that you drink plenty of fluids (2-3 litres per day). This can include both hot and cold drinks, though try to avoid having too much caffeine. This is even more important if you have increased the amount of fibre in your diet, as eating fibre without fluids can make constipation worse.

Physical activity

Taking some gentle exercise, such as walking or jogging, can also help to ease constipation. Regular physical activity also helps to prevent constipation.


Some medications taken to relieve other symptoms in secondary breast cancer (e.g. anti-sickness medications and moderate to strong painkillers such as Codeine and Morphine) can cause constipation. However, it is important for you to speak to your doctor or nurse before reducing or stopping these medications, since this may cause other symptoms to worsen.

Laxatives are medications which help you to open your bowels. There are different types of laxatives which work in different ways to treat different causes of constipation. Your doctor or nurse will be able to recommend the best one for you. Some of these medications are available without a prescription, though it is important for you to speak to your medical team before beginning any new medication for your constipation.

It is important to take laxatives as they are prescribed, or as advised by the pharmacist if bought over the counter, and to not exceed the maximum recommended dose. It is also crucial to take these regularly, since it is easier to prevent constipation than to treat it once it has become a problem.

Chronic constipation

Where constipation continues over a longer period of time, this is known as chronic constipation. If you are regularly constipated over long periods of time, faecal impaction can occur. This is where a large amount of hard, dry stool (poo) is stuck in the rectum (the bottom end of the bowel).

Over time, this can be caused by;

  • Medications such as painkillers and laxatives
  • Lack of exercise over a long period of time
  • Depression & anxiety
  • Diet low in fibre

Symptoms of impaction are similar to constipation, though more serious ones can occur;

  • Back pain (due to the mass of poo pressing on the nerves in your back)
  • Swollen tummy
  • Severe stomach pain or cramps
  • Dehydration
  • Dizziness
  • Sweating
  • Feeling or being sick
  • High temperature
  • Confusion

If you think that you might have any of these symptoms, or are worried that you have had constipation for a long time, please call your hospital to speak to your doctor or nurse.

Disclaimer: on this website you will find self-management advice to help you to manage a range of mild symptoms and side effects of secondary breast cancer and its treatment. Please ONLY use this advice if you are currently participating in the LIBERATE study. Otherwise, please follow the advice of your own healthcare team.

Page last updated: April 2020