Bowel Changes: Diarrhea and Constipation



  • implies a change in a person's bowel habits, including increased fluidity, increased frequency, or the presence of abnormal products such as blood, pus or mucus
  • there is tremendous variation in "normal" bowel function among individuals, therefore the diagnosis of diarrhea must be individually evaluated
  • diarrhea may occur in cancer patients for a variety of reasons, including:
    • hormone-secreting tumors ( carcinoid syndrome, villous adenoma of colon)
    • deficiency of pancreatic enzymes or bile salts
    • infiltration of the small bowel by cancer
    • partial upper bowel obstruction
    • malnutrition
    • lactose intolerance
    • radiation therapy to abdomen or chemotherapy
    • nutritional supplements
    • bacterial or viral infections
    • anxiety or stress
    • surgical resection of bowel
    • other medications
  • diarrhea is caused by 3 major physiologic mechanisms
    • osmotic diarrhea - excess fluid in the stools as a result of decreased net absorption in the intestine
    • secretory diarrhea - increased net secretions by the intestines
    • hyper motility states - combination of these two types


  • assess the normal bowel function for this patient and identify the changes from their normal patterns
  • may be helpful to quantify the number/amount of stools per 24 hrs.
  • review dietary intake and recent changes in diet
  • evaluate nutritional supplements or tube feedings as source of diarrhea
  • check weights weekly


  • nutritional intervention encourage fluids (2 3 quarts/day)
    • small frequent meals
    • high protein and carbohydrate intake
    • try low residue foods such as bananas, applesauce, rice
    • avoid foods that are too hot or too cold which may stimulate GI activity
    • avoid milk and milk products if lactose intolerant
  • medications
    • bulk-forming agents (e.g.. methyl cellulose and psyllium)
    • absorbents (e.g.. kaolin and pectate) helpful when there is an excess of bile salts
    • antacids - most contain magnesium and act as osmotic agents to stimulate elimination, those that contain aluminum are used to alleviate loose stools
    • narcotic agents - opium derivatives (paregoric, tincture of opium, belladonna), diphenoxylate hydrochloride, codeine, imodium



  • defined as the passage of hard, dry stools, associated with an undue amount of straining that may be decreased in frequency from normal
  • based on the subjective report of the patient
  • constipation may occur in cancer patients for a variety of reasons, including:
    • decreased intake of food or dietary fiber
    • dehydration
    • narcotics
    • lack of physical activity
    • immobility
    • tumor invasion or compression of the bowel
    • chemotherapy, including vinca alkaloids
    • spinal cord or cerebral injury or tumor
    • hypercalcemia


  • assess daily dietary fiber, calorie and fluid intake
  • review current medications and treatments that may cause or contribute to constipation
  • assess the frequency and consistency of stools as well as any other complaints the patient may have
  • evaluate for spinal cord involvement contributing to the cause
  • assess for leukopenia or thrombocytopenia prior to initiating any treatments


  • provide a high fiber diet with approx. 5 10 gms. of dietary fiber daily
  • ensure adequate fluid intake, 2-3 liters per day
  • increase activity as tolerated
  • see laxative protocol
  • laxatives
    • bulk producers (eg.bran, cellulose, calcium polycarbophil) are hydrophilic agents that absorb large amounts of water in the gut, thereby softening as well as increasing the size of the stool
    • lubricants (e.g.. mineral oil) lubricate and soften the stool
    • osmotic or saline laxatives (e.g.. milk of magnesia, Epsom salts, magnesium citrate, lactulose) retain water in the small bowel,increase flow of fluid into the colon
    • stimulant or contact laxatives (e.g.. castor oil, senna, cascara, bisacodyl) work by inducing peristalsis through intrinsic stimulation of the colon
    • suppositories and enemas stimulate sensory receptors in the rectum
  • use caution in the neutropenic patient as they are at high risk for infection and the use of suppositories and enemas may increase that risk


Basch, A. (1994)." Elimination" in Gross, J., Johnson, BL. Handbook of Oncology Nursing, 2nd ed. Boston: Jones and Bartlett, 1994.

Bisanz, A. (1997). Managing bowel elimination problems in patients with cancer. Oncology Nursing Forum, 24 (4), 679-86.

Doughty, D. (1991). Maintaining normal bowel function in patients with cancer. Journal of Enterostomal Therapy Nursing, 18 (3), 90-94.

Addendum: Sample Laxative Protocol

Most cancer patients will experience constipation at some time during the course of their illness. The goal of a bowel regimen is to prevent constipation when possible and then to treat it when necessary. The nutritional guidelines of a diet high in fiber and fresh fruits and vegetables as well as the intake of 6 to 8 glasses of water per day may prevent the need for laxatives. Check with the patient's doctor before recommending any brand of laxative or any change in laxative.

The following protocol sheet may be helpful for your patient and their care givers. After conferring with the physician, fill in the appropriate brand and dose of medication and leave this sheet in the house with the patient.

Laxative Protocol

Many prescription medications can cause constipation. Bowel function is also affected by activity and diet. For example, regular doses of narcotic pain-relieving medication frequently cause constipation. A medication regimen that also includes use of a laxative is almost always required to prevent constipation.

A daily bowel regimen should be followed just as carefully as your doctor's other instructions. The overall goal is to have a bowel movement approximately every days(s). Because responses vary, use the guidelines below to find a regimen that works best for you. If at any time the dosage of your pain-relieving medication is changed, you may also need to increase or decrease your daily dosage of laxative. See your doctor for a change in dose.

1. Take at bedtime,
Brand and dose

If you do not have a bowel movement in the morning,

2. Take after breakfast.
Brand and dose

If you do not have a bowel movement by evening,

3. Take at bedtime.
Brand and dose

If you do not have a bowel movement in the morning,

4. Take after breakfast.
Brand and dose

If there is no bowel movement within 48 hours after starting this protocol,

5. Add after breakfast, while continuing to take in the morning and tablets in the evening.

If there is no bowel movement within hours after beginning this protocol, please consult your physician for additional instructions.

Once you start have bowel movements, use the two steps prior to your last one as your daily laxative protocol. For example, if you achieved a bowel movement after Step 4, use Steps 2 and 3 (that is, (3) in the morning and at bedtime) as your daily regimen.

Remember, constipation is a common side effect of many medications. A daily bowel regimen helps to prevent this potentially troublesome side effect.

If you are unsure about what to do, please call your physician for advice.