When you’re having chemotherapy treatment, you may find that you have difficulty emptying your bowels. Chemo can cause trouble with bowel movements, or constipation, for a number of reasons. However, there are things you can do to help relieve the symptoms.

In this post we take a look at why chemo can leave you with constipation, and what steps you can take to make things more comfortable.

What causes chemo-related constipation?

Many people who have chemotherapy find that it can affect their bowel movements. Chemotherapy drugs can make your stools (poo) harder, less regular and more difficult to pass. Constipation can also be accompanied by other symptoms, including bloating, cramping or aching, a sense of fullness, pain or bleeding, flatulence (gas) and nausea. Please note, if you are bleeding from your back passage as a result of constipation, this may need medical attention.

When you’re having chemo, there are a number of factors that can affect how well your bowel is functioning. These include:

  • The chemicals in the chemo – the specific chemicals used in the chemotherapy treatment can sometimes affect the nerve supply to your bowel, which can in turn affect your bowel movements. Some chemo treatments can also cause damage to the cells in the lining of the digestive tract (gut), causing problems with constipation.
  • Other medications – if you’re taking other medications to deal with the side effects of your chemo – such as anti-nausea drugs or painkillers – these can also make constipation worse. It’s worth talking to your medical team about your symptoms as they may be able to make some adjustments.
  • Changes to your eating habits – when you’re undergoing treatment, you may well find that your eating and drinking habits change. For example, you may not feel like eating as much because of nausea, and you may not be getting enough fibre and fluid in your diet, which can lead to constipation. Dietitian referrals can be made by your medical team to help with dietary advice.
  • A lack of exercise – when you’re having chemo you may find you are less active than normal. A lack of mobility can weaken the muscles in your stomach and bowel and affect the movement of your gut, causing things to slow down and making your bowel movements less regular. Physio referrals can be made by your medical team for advice on exercise.
  • Anxiety and depression – having chemo treatment can be an emotional time. Some people suffer from anxiety or depression, and this can have an effect on the nerves and muscles that control the function of the bowel.

How can I manage chemo-related constipation?

It’s important to remember that the symptoms are likely to start improving after your treatment has finished, and there are lots of things you can do in the meantime to help manage constipation – or better still to try and prevent it!

1) Eat plenty of fibre

When you’re having chemo, it’s even more important to make sure you have plenty of fibre (or roughage) in your diet. Fibre helps your digestive system to stay healthy and regular, by keeping food moving through the gut and assisting with the removal of waste and toxins.

You can increase your fibre intake by eating whole wheat cereals, wholemeal bread and pasta, brown rice, nuts and seeds, beans and pulses, and plenty of fruit and vegetables (ideally with the skin or peel on). If you have difficulty eating during treatment, you could try making a smooth vegetable soup or fruit juice instead.

See a range of products designed to help with feeling sick here.

Many people recommend trying a natural remedy for constipation, such as prune juice, fig syrup, or dried apricots:

“Prune juice helps with constipation, it’s quite pleasant to drink. You can also try eating prunes or figs, fresh or dried.” Gillie, Live Better With community member.

Some people also recommend using a supplement, such as soluble fibre, or adding chia seeds or flax seeds (linseeds) to their diet, which can help to improve digestive function and cleanse the bowel:

“I really love this stuff. I sprinkle it on my morning cereal, in yoghurt, in stews and soups, in fact it will go in almost anything. It tastes good too and is high in antioxidants. Good in the fight against cancer and lowering of cholesterol.” Live Better With community member.

Note: it’s important to always check with your doctor before taking any kind of supplements.

You can read the full Live Better With guide to Cancer and Eating Well here.

2) Keep your fluids up

A lack of fluid, or dehydration, is another common problem when you’re having chemo. Dehydration can make constipation worse as water will be drawn back into your body from your bowel, making stools harder and more difficult to pass.

You can help to keep your stools soft by drinking plenty of fluids. This is even more important if you are increasing the amount of fibre in your diet!

You should aim to drink around eight to ten glasses of water or other non-alcoholic drinks, such as fruit juices or soups, every day. Try to avoid having alcohol or large amounts of caffeine, as these can cause dehydration.

3) Get some exercise

Exercise can become more difficult when you’re undergoing chemo. You are likely to need plenty of rest, and you may be experiencing side effects such as nausea and fatigue (tiredness).

However, doing some gentle exercise every day is known to help keep your gut moving, improving digestion and bowel function and reducing the risk of constipation.

Regular exercise can also help to stimulate your appetite, improve sleep and boost your mental well-being.

Try taking a short walk in the fresh air, or doing some yoga stretches. If you can’t get out and about, a pedal exerciser, exercise ball or resistance bands can be a helpful way of keeping your core muscles moving.

Remember to check with your doctor first, and be sure to do things at your own pace.

See the Live Better With Guide to Exercise to find what could work for you.

4) Keep to a routine

Everyone is different, and has a different bowel pattern. However, if chemo and its side effects are affecting how much you are eating, this is likely to lead to a decrease in your normal bowel movements.

To reduce the risk of constipation, you should try to eat at regular times each day. Similarly, you should try to go to the toilet at regular times, and whenever you feel the need to open your bowels. Make sure you are as relaxed and comfortable as possible – using a footstool can help with this.

It can also be helpful to keep a note of your bowel movements and any diet and lifestyle changes you are making, so you can see what works.

5) Look after your mental health

When you’re having chemo, it can be an anxious time. It’s common to feel worried, anxious or depressed – and this can affect your bowel function, which can lead to constipation.

Meditation, mindfulness and deep breathing can be very helpful in relieving stress and anxiety. The Live Better With community recommends The Little Book of Mindfulness, which contains a range of stress-busting techniques:

“This book is well written and concise. It’s small enough to keep in your bag and dip into whenever you want to. I have found it invaluable in helping me to relax and unwind. It also helps in controlling pain and is as good if not better than medication.” Sam, Live Better With community member

Click here for a range of products designed to help you relax and unwind, from books, CDs and DVDs to adult colouring books and aromatic diffusers.

It’s also important to be able to talk to someone you trust about how you are feeling, such as a friend or family member. Online forums can also be a good source of advice and support, from people who have been through a similar experience.

When should I see a doctor about my constipation?

If you’re struggling with constipation as a result of your chemo treatment, despite making diet and lifestyle changes, it’s important to talk to your medical team. There are a range of medications which may be able to help, including laxatives, emollients (stool softeners) and lubricants, and they can advise on what’s suitable for you.

You should also contact your doctor if you are suffering from pain, swelling or hardness in your stomach, fever, nausea or vomiting, or if you have not had a bowel movement for 2-3 days despite following any advice given.


Constipation can be a common side effect of chemotherapy. However, by making some simple diet and lifestyle changes you can help to reduce the effects and make life more comfortable.

Do you have any tips for managing constipation during chemo, or are you looking for more advice? Visit the Live Better With cancer forum.