Changes in bowel habits, such as constipation, are common problems for people with cancer. Constipation is the passing of infrequent, hard or dry stool, usually accompanied by discomfort. The stool becomes hard and dry if it moves too slowly through the large intestine (bowel) or if the intestine absorbs too much water from it. Constipation affects about one half of all people with cancer.
Causes
Constipation can be caused by a number of factors including the cancer itself or cancer treatments. The cells lining the gastrointestinal tract are rapidly dividing cells, so they can be easily damaged by treatments such as chemotherapy and radiation therapy.
Factors that increase the risk of developing constipation:
- decreased fluid intake and dehydration
- loss of appetite (anorexia)
- lack of fibre or bulk-forming foods in the diet
- certain drugs
- pain relievers, especially opioid narcotic medications, such as morphine or codeine
- chemotherapy drugs, such as the vinca alkaloids (vincristine and vinblastine)
- anti-nausea drugs, such as ondansetron (Zofran), granisetron (Kytril) or dolasetron (Anzemet)
- antidepressant drugs
- overuse of laxatives
- vitamin or mineral supplements such as iron or calcium pills
- decreased physical activity or bed rest
- depression
- cancer growing into the large intestine (bowel)
Symptoms
A person may have to strain to pass stool and may also have:
- abdominal bloating
- abdominal cramping or pain
- gas (flatulence)
- loss of appetite
Diagnosis
To help find out the cause of constipation, the doctor may:
Prevention
There are many ways a person can help prevent constipation:
- Gradually add more fibre and roughage to the diet. Whole grain breads and cereals, fruits, vegetables, legumes (beans), dried fruits, seeds and nuts are examples of foods that are excellent sources of fibre.
- Include plenty of fluids throughout the day to help move that extra fibre through the bowel. Drink 8 to 10 glasses of fluid each day. Fluids include water, prune juice and other fruit and vegetable juices, decaffeinated teas, lemonade, broth, jello and popsicles.
- Try a hot drink about 30 minutes before the time a bowel movement usually occurs.
- Eat a breakfast that includes a hot liquid and foods high in fibre.
- Eat foods that act as natural laxatives (prunes, prune juice, rhubarb and papaya). Fruit lax, a jam-type spread made from prunes, dates and other dried fruits, can be made and used on toast or crackers or used with ice cream or yogurt.
- Add small amounts of bran to cooking or baking.
- Talk to the dietitian about ways to use or prepare natural laxative foods in a daily diet.
- Increase physical activity if possible.
If constipation persists, it can cause the stool to become packed in the colon or rectum (fecal impaction). A large amount of stool collects and because it is very hard and dry, a person has difficulty passing it. Sometimes the person will leak stool or have loose stool as it tries to move around the impaction. Fecal impaction can become a serious problem. It is important to try to prevent constipation and impaction.
Management
Tell the doctor if you have or are having trouble passing stool regularly or if you have not had a bowel movement for 3 days or more. The healthcare team will try to determine the cause of constipation and take measures to treat it. Do not use over-the-counter medications before checking with your doctor. If you are taking opioid narcotic drugs to relieve pain, you will need a bowel routine to prevent constipation.
The healthcare team may suggest one of the following:
- stool softener
- to help the stool retain water and keep it soft
- example: docusate (Colace, Surfak)
- laxative
- to help promote bowel activity
- example: senna or sennosides (Senokot), magnesium salts (Milk of Magnesia), mineral oil, lactulose
- to increase fibre or produce bulk
- example: psyllium (Metamucil)
- not recommended for people who are constipated due to pain medications or opioids, because they can cause constipation higher up in the colon
- suppository
- to help promote bowel activity
- example: glycerine, bisacodyl (Dulcolax)
- enema
- to clean out the bowel
- example: phosphate enema (Fleet), tap water
Sometimes a stool softener and a laxative are used together. A suppository or enema may not be recommended when white blood cell or platelet counts are low.
For more information on various laxatives, go to Cancer Care Ontario's Drug Formulary website.