Diet and nutrition after bowel cancer treatment

Diet and Nutrition after Treatment

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This page contains information on diet and nutrition after treatment for bowel cancer. You will find that your digestion takes time to settle down after bowel cancer treatment. Some foods can upset the way your bowel works. After treatment, high fibre foods, such as fruit and vegetables, may give you loose stools. You may need to go to the toilet much more often than normal. If you have had a colostomy you may find that it takes a few months for your bowel to work normally again. If you have had a combination of treatments, you may have permanent changes to your bowel. You may need to avoid certain foods.

Some foods can cause wind, which will go into your stoma bag if you have a colostomy or ileostomy. You may need to experiment a bit to find out which foods upset your system. The foods most likely to cause problems are:

  • Very high fibre fruits and vegetables;
  • Onions, brussel sprouts and cabbage;
  • Pulses such as baked beans or lentils;
  • Fizzy drinks, beer and lager; and
  • Very rich or fatty foods.

Diet after bowel cancer surgery

When you are well enough to go home after your operation, you will be eating fairly normally. You may be on a low fibre diet for about 6 weeks. You can then gradually increase the amount of fibre in your diet.


The large bowel (colon) normally absorbs water as the stool passes through it. So if you have had part of your large bowel removed, your stool may become less solid. If you have had a large part of it removed, you may have diarrhoea. Let your doctor or nurse know if this happens, as they can give you medicine to help control it. It is important to drink plenty of fluids if you have diarrhoea. If you are drinking a lot and still feel thirsty you may need to have a drink that replaces fluid and body salts (an electrolyte replacement drink). Your doctor can advise you about this.

Some foods may upset your bowel

You may find that your bowel starts to work more normally after a few weeks. But particular foods may upset things. You may need to experiment with your diet to find out which foods cause a problem for you. As the bowel settles down you may find that you can start to eat these foods again later on. Everyone is different and there are no set rules about what you should eat. If you have problems you can ask to see a dietitian at the hospital. They can give you tips and help you to work out which foods upset you.

It can help to keep a food diary before you go to see the dietitian. The diary is a record of:

  • What you eat
  • When you eat
  • Any digestive problems and when you have them.

Looking back over a weekly diary you may be able to spot which foods are causing you problems and then cut them out. You may be able to try the food again in a few weeks to see if it causes the same problem.

Tips for diet after bowel cancer surgery

Eat foods high in calories and protein to help with healing and fighting infection. High protein foods include meat, fish and eggs.

Eat small, more frequent meals to begin with rather than 3 large meals a day. Try to avoid long gaps between meals.

It may help to eat a low fibre diet at first. Examples of low fibre foods are:

  • White pasta and bread;
  • Cream crackers;
  • Rich tea biscuits;
  • Cornflakes; and
  • Vegetables and fruit that are well cooked and peeled.

Drink plenty of fluids – at least 3 to 4 pints or 1.5 to 2 litres a day.

Reduce the amount of caffeine you have in a day. Caffeine can stimulate the bowel and make diarrhoea worse.

Take small mouthfuls and chew your food slowly.

Drinking peppermint water may help relieve trapped wind and so ease discomfort.

Diet after radiotherapy

Radiotherapy to the bowel often causes diarrhoea. This can take a few weeks to settle down after the treatment ends. Your doctor can give you tablets to help control the diarrhoea. If it doesn’t improve within 4 to 6 weeks of finishing your treatment, let your doctor know.

While you are getting over your treatment it is best to keep taking the diarrhoea medicines. You can gradually reduce the amount you take. Your doctor or nurse will advise you about how to manage this.

Diet and chemotherapy

Chemotherapy for bowel cancer can give you diarrhoea and may make you feel sick. You may also have a sore mouth. These side effects will disappear after your treatment is over. You can gradually get back to a normal diet.

Diet with a stoma

It normally takes about 6 to 8 weeks for the bowel to settle down after surgery. After this, most people can go back to eating the foods they used to eat before their operation. Your stoma nurse will give you advice about what you can eat and drink shortly after your operation and in the long term.

Diet with a colostomy

Generally you can eat what you like. But some people may find that particular foods cause problems such as wind, a bad smell or looser stool (poo). It’s often down to trial and error to find out if a particular food disagrees with you. You can try the food again after a few weeks to see if it is still causing a problem. Once your bowel settles down after your operation, you can gradually increase the amount of fibre in your diet. This will help your stool to be more formed.

Diet with an ileostomy

When going back to your normal diet, it’s a good idea to introduce one food a day at first. You can keep a food diary and make a note if a particular food causes cramps or diarrhoea. If so, you can try it again in a few weeks to see if it has the same effect. The small bowel is narrower than the large bowel, and so some foods such as celery, tough fruit skins, nuts and mushrooms, may cause a blockage. This is usually only temporary but can cause pain and cramps. When you start to eat these types of foods again, try eating them in small portions and chew them really well. You lose more fluid through an ileostomy, so it is important to drink plenty.


Other resources

If you are undergoing treatment for bowel cancer, this website has information on topics such as:

You can also download a copy of the free booklet, ‘Bowel Cancer: From diagnosis to recovery‘ here.

Bowel Cancer Booklet
‘Bowel Cancer: From diagnosis to recovery’ is a free booklet that is available for download from the Marie Keating Foundation


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