Constipation and cancer

Dietitian, Annica Rust, shares advice on what food to eat when experiencing constipation.


Talking about constipation might be an embarrassing and slightly uncomfortable topic to have with a practitioner. Though, it shouldn’t be a taboo topic, as almost half of all cancer patients might experience constipation throughout their cancer journey1. 

Constipation is perceived and experienced differently amongst cancer patients. 

Take a sneak peak

Constipation can be defined as having difficulty with bowel movements. It is characterised with fewer bowel movements than usual that might be painful, small, hard and sometimes difficult to pass1,2,3.  

Don’t be shy and take a sneak peek before you flush.  

Long sausage-like stools are ideal stools to have and will be easier to pass4. The frequency of a normal bowel movement can vary between three times per day and three times per week2.

Reasons for constipation

The most common reasons are a low intake of dietary fibre and fluids and a lack of physical activity. It can also be caused by medications, iron and calcium supplementation, laxative abuse and medical diseases, such as diabetes, thyroid problems, depression, Parkinson’s disease and cancer1,2,5. Constipation is common amongst the elderly as colonic function will decrease with age 2,5. 

Why do cancer patients have an increased risk of constipation?

Cancer patients often eat less, don’t drink enough fluids and don’t consume enough fibre. They are also not as active as they used to be before diagnosis. 

Furthermore, medication for nausea, pain and some chemotherapies can slow down your digestion and will increase your risk for constipation. Often the disease itself, such as colon cancer, can cause constipation or a bowel obstruction where waste can’t leave your digestive system. 

Surgery or radiation to the bowel area might cause scar tissue around or inside the bowel and can also increase the risk for constipation and bowel obstruction. Except for being uncomfortable, if left untreated, it can damage your digestive system and rectum1.

Dietary tips to treat and prevent constipation:

  1. Increase your fluid intake. Consider using warm fluids, such as hot lemon water, rooibos tea or decaffeinated coffee in the morning2,3. Avoid drinks with caffeine, such as coffee and tea (black and green), because they’re classified as diuretics and can leave you dehydrated without adequate fluid intake. You should confirm the amount of fluids to be consumed with a doctor/dietitian.
  2. Slowly increase fibre intake to minimise flatulence and bloating. Check with a doctor/dietitian before starting, especially if you had surgery to your bowel area1. Increase both soluble (vegetables, fruits, oats and legumes) and insoluble (whole-wheat products and some vegetables, such as cauliflower, potatoes and green beans) fibre intake2. Soluble fibre absorbs water and will become “sticky” with liquids and is good for constipation and diarrhoea. Insoluble fibre will not change but is better to consume when constipated6. A high-fibre diet is considered to have 25 – 38g of fibre per day. Try to consume six to 11 servings of whole-grain breads, cereals, flours, and other whole-grain products per day and try to consume five to eight servings of vegetables, legumes and fruits, nuts, and edible seeds per day2. For a high-fibre diet of approximately 24g of dietary fibre, use 12 or more servings of the foods from the groups below (each food contains approximately 2g of dietary fibre)2.

    Foods

    Amount Foods Amount
    Apple 1 small/ 100g  Strawberries ½ cup
    Orange 1 small/ 100g Cherries 10 large
    Banana 1 small/ 100g Plums 2 small
    Peach 1 medium Oats, dry 3 tbsp
    Whole-wheat bread 1 slice Baked beans 2 tbsp
    Rye bread 1 slice Celery 1 cup
    All Bran Flakes 1 tbsp Tomato, raw 1 medium
    Broccoli ½ stalk Corn on the cob 1 cob
    Lettuce 2 cups Baked beans 2 tbsp
    Green beans ½ cup Potato 100g
    Carrots ⅔ cup Wheat bran 1 tsp
  3. Increase your activity if possible. Check with your healthcare provider before starting. Activity will help to move food through your stomach to your colon. This will make bowel movements easier1,2,5.
  4. Consider using foods that contains probiotics, such as yoghurt2.
  5. Try go to the bathroom the same time every day. Your body will get used to the routine. However, don’t ignore an urge to have a bowel movement and allow enough time or privacy to do your business5. Reflexes in your colon are the strongest in the morning; it might therefore be the best time to plan for your bathroom visits in the morning5.

Food always comes first; discuss the usage of laxatives/fibre supplements andwhich ones to use with your doctor/dietitian before using them. If you experiencebloating together with pain and fever, contact your doctor immediately. Don’t self medicate with food and laxatives6.


References:

  1. ASCO. ASCO answers: Constipation. American Society of Clinical Oncology.2019; 1(1):1.
  2. Cresci, G. & Escuro, A. Medical nutrition therapy for lower gastrointestinal tract disorders. Mahan, L.K. & Raymond, J.L. (eds). Krause’s food and the nutrition care process. 14th ed. St Louis. MO: Elsevier Saunders: 2017.
  3. American Cancer Society. Constipation. 2015; 1(1):1. https://www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/stool-or-urine-changes/constipation.html
  4.  Lewis, S.J. & Heaton, K.W. Stool form scale as a useful guide to intestinal transit time. Scandinavian Jorunal of Gastroenterology. 1997; 32: 920–4
  5. Memorial Sloan Kettering Cancer Center. Constiaption. 2018. https://www.mskcc.org/cancer-care/patient-education/constipation
  6. Dixon, S. Constipation, Diarrhea and Fiber.2013. https://www.oncologynutrition.org/erfc/eating-well-when-unwell/chemotherapy/constipation-diarrhea-and-fiber
Annica Rust is a registered dietitian practicing at the Breast Care Unit in Netcare Milpark Hospital as well as in Bryanston. She assists with medical nutritional therapy for cancer prevention, treatment, survivorship and palliation. She gives individualised nutritional care to prevent or reverse nutrient deficiencies, nutrition-related side effects and malnutrition to maximise quality of life.

MEET OUR EXPERT – Annica Rust

Annica Rust is a registered dietitian practicing at the Breast Care Unit in Netcare Milpark Hospital as well as in Bryanston. She assists with medical nutritional therapy for cancer prevention, treatment, survivorship and palliation. She gives individualised nutritional care to prevent or reverse nutrient deficiencies, nutrition-related side effects and malnutrition to maximise quality of life.