Key Points for this Section
Description and Causes
Common factors that may cause constipation in healthy people are eating a
low-fiber diet, postponing visits to the toilet, using laxatives and enemas
excessively, not drinking enough fluids, and exercising too little. In persons
with cancer, constipation may be a symptom of cancer, a result of a growing
tumor, or a result of cancer treatment. Constipation may also be a side effect
of medications for cancer or cancer pain and may be a result of other changes
in the body (organ failure, decreased ability to move, and depression). Other
causes of constipation include dehydration and not eating enough. Cancer,
cancer treatment, aging, and declining health can contribute to causing
More specific causes of constipation include:
- Not drinking enough water or other fluids.
Changed Bowel Habits
- Repeatedly ignoring the urge to pass stool.
- Using too many laxatives and enemas.
Immobility and Lack of Exercise
- Spinal cord injury, spinal cord compression, bone fractures, fatigue,
weakness, long periods of bedrest.
- Inability to tolerate movement and exercise due to respiratory or
Muscle and Nerve Disorders (nerve damage can lead to loss of muscle tone
in the bowel)
- Brain tumors.
- Spinal cord compression from a tumor or other spinal cord injury.
- Stroke or other disorders that cause muscle weakness or movement.
- Weakness of the diaphragm or abdominal muscles making it difficult to
take a deep breath and push to have a bowel movement.
Body Metabolism Disorders
- Needing assistance to go to the bathroom.
- Being in unfamiliar surroundings or a hurried atmosphere.
- Living in extreme heat leading to dehydration.
- Needing to use a bedpan or bedside commode.
- Lack of privacy.
Assessment of Constipation
A medical history and physical examination can identify the causes of
constipation. The examination may include a digital rectal exam (the doctor
inserts a gloved, lubricated finger into the rectum to check for stool
impaction) or a test for blood in the stool. If cancer is suspected, a
thorough examination of the rectum and colon may be done with a lighted tube
inserted through the anus and into the colon. The following questions may be
- What is your normal bowel pattern? How often do you have a bowel
movement? When and how much?
- When was your last bowel movement? What was it like (how much, hard or
soft, color)? Was there any blood?
- Has your stomach hurt or have you had any cramping, nausea, vomiting, pain, gas, or feeling of fullness near the rectum?
- Do you use laxatives or enemas regularly? What do you normally do to
relieve constipation? Does this usually work?
- What kind of food do you eat? How much and what type of fluids do you
- What medicine are you taking? How much and how often?
- Is this constipation a recent change in your normal habits?
- How many times a day do you pass gas?
Treatment of constipation includes prevention (if possible), elimination of
possible causes, and limited use of laxatives. Constipation caused by opioid pain medicine may be treated with a drug given by injection. Suggestions for the patient's
treatment plan may include the following:
- Keep a record of all bowel movements.
- Increase the fluid intake by drinking eight 8-ounce glasses of fluid
each day (patients who have kidney or heart disease may need to limit fluid intake).
- Exercise regularly, including abdominal exercises in bed or moving from
the bed to chair if the patient cannot walk.
- Increase the amount of dietary fiber by eating more fruits (raisins,
prunes, peaches, and apples), vegetables (squash, broccoli, carrots, and
celery), 100% whole grain cereals and breads, and bran. Patients must drink
more fluids when increasing dietary fiber or they may become
constipated. (See the PDQ summary on Nutrition in Cancer Care for more information.) Patients who have had a bowel obstruction or have undergone
bowel surgery (for example, a colostomy) should not eat a high-fiber diet.
- Drink a warm or hot drink about one half-hour before the patient's usual
time for a bowel movement.
- Provide privacy and quiet time when the patient needs to have a bowel
- Help the patient to the toilet or provide a bedside commode instead of a
- Take only medications prescribed by the doctor.
- Do not use suppositories or enemas unless ordered by the doctor. In
some cancer patients, these treatments may lead to bleeding, infection,
or other harmful side effects.
Current Clinical Trials
Check NCI’s list of cancer clinical trials for U.S. supportive and palliative care trials about constipation, impaction, and bowel obstruction that are now accepting participants. The list of trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.