Bowel problems

Treatment can alter your normal bowel habit causing constipation or diarrhoea. Consult your cancer doctor if symptoms persist. (These recommendations need to be adjusted for people with some types of cancer; for example bowel cancer.)

Constipation (hard bowel motions)

If you are constipated, increasing the fibre content of your diet can help:

  • Eat regular meals.
  • Do some exercise each day.
  • Increase the amount you drink. Aim for 8 to 10 glasses each day. Hot drinks may help.
  • Ensure you are having 5+ servings of fruit and vegetables each day. Eat raw or cooked.
  • If too much wind is a problem, try avoiding vegetables that may cause wind or discomfort, such as cabbage, onions, cucumber, peas, and baked beans, and limit fizzy drinks.
  • Choose wholemeal or wholegrain breads and cereals; for example porridge, Weetbix, All Bran, muesli, wholemeal bread, wheat germ, bran biscuits, or muffins. Use wholemeal flour for baking or in sauces.
  • Commercial products, such as Kiwicrush, Benefiber, Metamucil, or Stimulance may be useful.
  • Kiwifruit, prunes, and their juices are helpful in preventing constipation.

Add extra fibre to your food; for example one or two teaspoons of wheat bran flakes or oat bran daily. This can be gradually increased to an amount that will give you a regular bowel habit. The bran can be added to cereals or used in cooking. When you use bran to increase your fibre it is important to increase your fluids as well.

See our fruit kebabs with yoghurt and honey dipping sauce recipe.

Prune mix

Try some of this prune mix daily.


1 cup pureed apple

1 cup bran flakes

½ cup softened prunes

1 cup prune juice


Puree together using a blender, stick blender, or food processor, and serve two to three tablespoons with breakfast daily.

Diarrhoea (loose bowel motions)

Some chemotherapy drugs cause severe diarrhoea. If you have diarrhoea, contact your cancer doctor or nurse immediately. Following an acute bout, gradually start eating bananas, rice, apples, and toast.

  • Drink more to replace lost fluids. Choose from diluted fruit juice, flat soft drink, vegetable juice, vegetable broth, weak tea, and nutritional supplements. Aim to drink at least eight glasses (1500ml) of fluid daily.
  • Eat small, frequent meals.

What is a low fibre diet?

Your dietitian or cancer doctor may advise you to eat a low fibre diet. A low fibre diet is when you have less of or none of these foods:

Breads and cereals

Breads that contain whole grains, nuts, seeds, and kibbled wheat; cereals, such as muesli, which contain nuts, seeds, or dried fruit; and brown rice or pasta.


Fruits with seeds, pips, pith, or hard skins; for example kiwifruit, berries, apples, citrus fruits, and dried fruit.


Vegetables with hard skins, seeds, or stalks; for example corn, celery, vegetables from the cabbage family, onions, cucumbers, garlic, peas, and broad beans.

Nuts and seeds

Crunchy peanut butter, nuts, and seeds—whole or chopped.

Meat, fish, poultry, eggs, and pulses

Tough, gristly meat, fried meat, fish, or poultry, fatty or highly seasoned meats, such as sausages, curry, prepared dried meals, fried eggs, baked beans, and pulses.

Other foods or drink that may make diarrhoea worse:


Alcoholic drinks, strong tea, or coffee.


Rich sauces, highly seasoned dressings, rich pastry, batter, and fried foods. Any new foods should be introduced one at a time, so that you can check their effect. You can gradually return to a normal diet.

If you have severe diarrhoea, see your cancer doctor. A low residue diet may be recommended.

Eating a low residue diet

This is the same as a low fibre diet plus the points below:

  • If you experience cramping pains, bloating, and diarrhoea (these can result if lactose (milk sugar) is not digested), you could try limiting the amount of cow’s milk you drink to 300ml daily. Hard cheeses are usually well-tolerated. Cow’s milk should be replaced with soy or rice milk, or nutritional supplement drinks. You will be able to tolerate lactose again after the diarrhoea has settled. Cow’s milk may then be re-introduced. Many people do tolerate milk products, and they should only be avoided if not tolerated on a regular basis.
  • It is wise to limit fruit and vegetables to three servings a day. All fruit and vegetables should be peeled and cooked without pips or seeds. You do not need to limit the fruit and vegetable juices you drink.
  • Use white bread for toast and sandwiches. Use cream crackers and water crackers for snacks. Only use baked or cereal products made from white flour; for example white rice, noodles, spaghetti, cornflakes, and rice bubbles. Avoid pepper, curries, foods containing spices, alcohol, and fatty foods.
  • Re-introduce foods one at a time so that you can judge their effect.

Intolerance to some foods (food that makes you feel unwell)

If you have had bowel surgery, you may find for a time that your body can no longer tolerate some foods that were a part of your diet. It will take time for your body to adjust to the changes made by the surgery but, usually, it will slowly return to a normal or near normal state. After a time (it may take some weeks or months), slowly introduce a new food into your diet. Try one new food at a meal, and start with a teaspoonful. Once you find that your body accepts the new food, you can increase the quantity. You will then be able to do the same for another new food.


You may experience extreme tiredness (fatigue) during or after surgery/treatment:

  • Eat small frequent meals.
  • Have a variety of foods to keep meals interesting and appetising.
  • Remove rules around eating.
  • You may find nutritional supplements useful (see information about nutritional supplements).

Use ready prepared foods, have two to three pre-prepared meals in the freezer for treatment days or days that you have a lot of appointments.

For more information on managing your fatigue, read our Information Sheet “Cancer-Related Fatigue” on the Society’s website.

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