Bowel problems and cancer - Maggie's Centres

Bowel problems and cancer


Bowel problems are common in people with cancer. They can be from the cancer itself, side effects of cancer treatment, and medication. Stress, anxiety and depression can also affect the bowel.

The most common problems are constipation and diarrhoea, although there can sometimes be a bowel obstruction (blockage), or stoma and ileostomy difficulties.

There are a number of strategies to help ease the symptoms of constipation and diarrhoea. The information on this page will help you to find out more about bowel problems, and ways to manage them, during and after cancer treatment.

Bowel problems

Bowel problems are a common problem during cancer and its treatments.  The main problems you may be aware of are constipation or diarrhoea - when your bowel habits change, and the symptoms are uncomfortable. Other symptoms  of bowel problems include pain, bowel cramps, bloating, and loss of appetite. Other symptoms  of bowel problems include pain, bowel cramps, bloating, and loss of appetite.

Chemotherapy, radiotherapy and surgery can temporarily change your bowel function. Medications, inactivity and a change in food intake can add to this problem. In addition, infections can lead to diarrhoea. Normal bowel movements vary from person to person, so it is what is normal for you which counts. 

Constipation is when it is difficult to empty your bowels and the stools are dry and hard. You may feel bloated and uncomfortable, and find trying to pass your stools painful. 

Diarrhoea is when the stools become loose and watery, and you may find you’re passing stools frequently. More than three times a day can be classed as diarrhoea. It is often accompanied with cramps, wind and discomfort.

If you are aware of a change to your normal bowel habits do discuss your concerns with your doctor and hospital team. It helps to sort the symptoms out early and to try and prevent the problems in the first place. (If you have an ileostomy or stoma you may need specific advice). 

Managing constipation

Constipation is uncomfortable, and it can build up gradually.  Your healthcare team will explain if this symptom is expected, and there are steps you can take to help prevent and manage the problem. 

Take stool softeners and/or laxatives as recommended by your healthcare team

Drink plenty of fluids, up to 8 glasses of water a day to help keep the stools soft and maintain a normal bowel habit.

Try some light exercise as this will help keep the bowel working smoothly.

Eating a high fibre diet can help, e.g. whole wheat breakfast cereals, wholemeal bread and pasta, brown rice, fruit and vegetables with skins on.  However, check with your healthcare team if this will be OK. (For some cancers, and treatments which affect the bowel, a high fibre diet isn’t recommended). 

Eating at the same time of the day, and regular meals can help restore a normal bowel habit. 

Taking time to go to the toilet, and not straining, or rushing, can help too.

Read our cancer support specialist’s blog ‘Cancer and constipation’ and the nutritional advisor’s blog  ‘Dealing with treatment side effects’ for additional tips and advice.

If the symptoms persist, tell your doctor, as constipation can cause complications. The bowel may become impacted (blocked by hard stool) and sometimes constipation can be a symptom of other cancer related problems.

Managing diarrhoea

Diarrhoea can feel more distressing than constipation sometimes. The urge to go to the toilet immediately adding to the general upset of the diarrhoea symptoms themselves. 

Your healthcare team will have explained that diarrhoea may happen with some of your cancer treatments. Sometimes diarrhoea is a mild and temporary side effect. 

It is a symptom that shouldn’t be ignored, as you could soon become dehydrated (dry) and this can cause lead to further problems.

Ask for, and take any medication to help ease the diarrhoea, as prescribed by your doctor. You may also be given some tablets to relieve the pain and cramps if they’re very uncomfortable.

Try and drink plenty of fluids, ideally 8 glasses of water a day, as this will help keep you hydrated.

Eat light meals only, avoiding high fibre foods, and avoid greasy foods, caffeine, and dairy foods. Try and eat small amounts little and often, rather than a big meal. Foods which might help bulk up the stool include rice, pasta, skinless potatoes, white bread, bananas, chicken and fish.

If you have your temperature is higher than normal, you pass blood or tarry stools, or the diarrhoea is becoming more frequent (4-6 times a day or more), then let your doctor/healthcare team know immediately.


What now?

Find out what bowel side effects are expected from your cancer treatments. 

Tell your doctor if you’re worried or the symptoms are ongoing or severe

Try the suggestions mentioned on this page, and through our links and blogs. 

Visit your local Maggie’s Centre for practical and emotional support from the Maggie’s team, and talk with others in our online forums or physical centres about what you’re going through physically and emotionally.


Find a centre

To find your nearest Maggie's centre, enter your postcode or town below.

Get in touch

Stay up to date with our news and fundraising by signing up for our newsletter.
Sign up