Diarrhoea is defined as an increase in stool frequency, accompanied by a decrease in stool consistency. In colorectal cancer, it can result from the toxicity of chemotherapy or radiotherapy treatment or surgical procedure. It can also occur when antibiotics or other drugs are administered. Depending on the case, it can be mild or severe.


Because diarrhoea can lead to dehydration, drink plenty of fluids (water, herbal teas, weak broths, low-sugar isotonic drinks) in small sips throughout the day.

Homemade isotonic drink:

Mix the juice of two lemons, a tablespoon of honey, a dessert spoon of sea salt and a dessert spoon of bicarbonate of soda in a litre of water. When these ingredients dissolve, leave it in the fridge until it is cool.

Have small servings of food frequently throughout the day.

Start with a liquid diet, e.g., rice water, and when it becomes well-tolerated, incorporate easily digestible foods such as mashed potatoes and carrots, boiled rice, white fish, or boiled chicken and baked or grated apples.

Toasted bread, breadsticks, cereals, meat, fish, eggs (French omelette, grilled chicken, fish en papillote), pasta, rice and rice soups, potato, wheat and tapioca, biscuit, crackers, etc.

Boiling, grilling, steaming, and baking in the oven are easier-to-digest cooking methods.

  • Wholegrain cereals and derivatives, raw fruits, vegetables, pulses, and nuts are not recommended.
  • Choose fruit without skin, baked in the oven or microwave, or preserved in juice, syrup, or strained juices. Fruit in syrup (such as apple, pear, and peach), quince or banana and well-ripened pear are good options.

Some suggested recipes:

  • Vegetables low in fibre (courgette, pumpkin, carrot) can be consumed in small quantities (test your tolerance to each vegetable) always without skin or its seeds and very well cooked, also in the form of soups or strained broths.
  • Also test tolerance to fruit and vegetable smoothies as all the fibre is removed in the blending process.
Some suggested recipes:

Butter, margarine, lard, mayonnaise, cream, milk cream, and baked goods, among others, are not recommended.

They can be gradually incorporated, depending on tolerance

Avoid coffee, chocolate, black tea, alcohol, and spicy condiments, such as pepper.

Sweets, fruit nectar, simple sugar or honey, chocolate, sweetened drinks, xylitol, sorbitol, etc. are not recommended.