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Information from PDQ -- for Health Professionals
Constipation, impaction, and bowel obstruction
208/03510
** OVERVIEW **
Constipation, impaction, and bowel obstruction are common problems for oncology
patients. The growth and spread of cancer, as well as its treatment,
contribute to these conditions.
Constipation is the slow movement of feces through the large intestine that
results in the passage of dry, hard stool. This can result in discomfort or
pain.[1] The longer the transit time of stool in the large intestine, the
greater the fluid absorption and the drier and harder the stool becomes.
Constipation may be annoying and uncomfortable, but fecal impaction can be
life-threatening. Impaction refers to the accumulation of dry, hardened feces
in the rectum or colon. The patient with fecal impaction may present with
circulatory, cardiac, or respiratory symptoms rather than with gastrointestinal
symptoms.[2] If the fecal impaction is not recognized, the signs and symptoms
may progress and result in death.
In contrast to constipation or impaction, an intestinal obstruction is a
partial or complete occlusion of the bowel lumen by a process other than fecal
impaction. Intestinal obstructions can be classified by three means: the type
of obstruction, the obstructing mechanism, and the part of the bowel involved.
Structural disorders, such as intraluminal and extraluminal bowel lesions
caused by primary or metastatic tumor, postoperative adhesions, volvulus of the
bowel, or incarcerated hernia, affect peristalsis and the maintenance of normal
bowel function. These disorders can lead to total or partial obstruction of
the bowel. Patients who have colostomies are at special risk of developing
constipation. If stool is not passed on a regular basis (generally, once a day
to several times a day), further investigation is warranted. A partial or
complete blockage may have occurred, particularly if no flatus has been
passed.[3]
Functional disorders such as inactivity, immobility, or physical and social
impediments (particularly inconvenient bathroom availability) can contribute to
constipation. Depression and anxiety caused by cancer treatment or cancer pain
can lead to constipation, either alone or with other functional and physiologic
disorders. Perhaps the most common causes are inadequate fluid intake and pain
medications. These are manageable. It should be noted that management of the
pediatric patient varies from the adult patient and should be adjusted
accordingly.
References:
1. Culhane B: Constipation. In: Yasko J, ed.: Guidelines for Cancer Care:
Symptom Management. Reston VA: Reston Publishing Company, Inc., 1983, pp
184-187.
2. Wright BA, Staats DO: The geriatric implications of fecal impaction.
Nurse Practitioner 11(10): 53-66, 1986.
3. Hampton BG, Bryant RA, eds: Ostomies and Continent Diversions: Nursing
Management. St. Louis, Missouri: Mosby Year Book, Inc., 1992.
** CONSTIPATION **
-- Etiology of constipation --
Common factors that contribute to the development of constipation in the
general population are diet, altered bowel habits, inadequate fluid intake, and
lack of exercise. Constipation can be a presenting symptom of cancer, or it
can occur later as a side effect of a growing tumor or treatment of the tumor.
For patients with cancer, additional causative factors are the tumor itself,
cancer-related problems, the effects of drug therapy for cancer or for cancer
pain, and other concurrent processes such as organ failure, decreased mobility,
and depression.[1] Physiologic factors include inadequate oral intake,
dehydration, inadequate intake of dietary fiber, or organ failure. Any or all
of these factors can occur because of the disease process, aging, debilitation,
or treatment. (Refer to the Nausea, Vomiting, Constipation, and Bowel
Obstruction in Advanced Cancer section in the PDQ summary on Nausea and
Vomiting.)
-- Causes of constipation and impaction --
Diet:
- Insufficient fiber or bulk in diet*
- Inadequate fluid intake*
Altered bowel habits:
- Repeatedly ignoring defecation reflex
- Excessive use of laxatives and/or enemas
Prolonged immobility* and/or inadequate exercise:
- Spinal cord injury or compression, fractures, fatigue, weakness, or
inactivity (including bedrest)
- Intolerance with respiratory or cardiac problems
Medications:
- Chemotherapy (e.g., vinca alkaloids)*
- Opioids or sedatives
- Anticholinergic preparations (e.g., gastrointestinal antispasmodics,
antiparkinsonism agents, and antidepressants)
- Phenothiazines
- Calcium and aluminum-based antacids
- Diuretics
- Vitamin supplements (e.g., iron and calcium)
- Tranquilizers and sleeping medications
- General anesthesia and pudendal blocks
Bowel disorders:
- Irritable colon, diverticulitis, or tumor*
Neuromuscular disorders (disruption of innervation leads to atony of the
bowel):
- Neurological lesions (cerebral tumors)
- Spinal cord injury or compression*
- Paraplegia
- Cerebrovascular accident with paresis
- Weak abdominal muscles
Metabolic disorders:
- Hypothyroidism and lead poisoning
- Uremia*
- Dehydration*
- Hypercalcemia*
- Hypokalemia
- Hyponatremia
Depression:
- Chronic illness
- Anorexia
- Immobility
- Antidepressants
Inability to increase intra-abdominal pressure:
- Emphysema
- Any neuromuscular impairment of the diaphragm or abdominal muscles
- Massive abdominal hernias
Atony of muscles:
- Malnutrition
- Cachexia, anemia, or carcinoma*
- Senility
Environmental factors:
- Inability to get to the bathroom without assistance
- Strange or hurried environment
- Excess heat leading to dehydration
- Change in bathroom habits (e.g., use of a bedpan)
- Lack of privacy
Narrowing of colon lumen:
- Could be related to scarring from radiation therapy, surgical anastomosis,
or compression from growth of extrinsic tumor
*Frequently seen in oncology patients
Constipation is frequently the result of autonomic neuropathy caused by the
vinca alkaloids, taxanes, and thalidomide. Other drugs such as opioid
analgesics or anticholinergics (antidepressants and antihistamines) may lead to
constipation by causing decreased sensitivity to the defecation reflexes, and
decreased gut motility. Since constipation is common with the use of opioids,
a bowel regimen should be initiated at the time opioids are prescribed and
continued for as long as the patient takes opioids. Opioids produce varying
degrees of constipation, suggesting a dose-related phenomenon.
Other diseases such as diabetes (with autonomic neuropathy) and hypothyroidism
may cause constipation. Metabolic disorders such as hypokalemia and
hypercalcemia also predispose cancer patients to developing constipation. Once
these disorders are corrected, constipation should subside.[1]
-- Assessment of constipation --
A normal bowel pattern is considered to be at least three stools per week and
no more than 3 per day; however, these criteria may be inappropriate for cancer
patients.[1,2] Constipation should be viewed as a subjective symptom involving
the complaints of decreased frequency with incomplete passage of dry, hard
stool. A thorough history of the patient's bowel pattern, diet changes, and
medications along with a physical examination can identify possible causes of
constipation. The evaluation should also include assessment of associated
symptoms such as distention, flatus, cramping, or rectal fullness. A digital
rectal examination should always be done to rule out fecal impaction at the
level of the rectum. A test for occult blood will be helpful in determining a
possible intraluminal lesion. A thorough examination of the gastrointestinal
tract is necessary if cancer is suspected.[3]
The following questions may provide a useful assessment guide:
1. What is normal for the patient: frequency, amount, timing?
2. When was the last bowel movement? What was the amount, consistency, and
color? Was blood passed with it?
3. Has the patient been having any abdominal discomfort, cramping, nausea or
vomiting, pain, excessive gas, or rectal fullness?
4. Does the patient regularly use laxatives or enemas? What does the patient
usually do to relieve constipation? Does it usually work?
5. What type of diet does the patient follow? How much and what type of fluids
are taken on a regular basis?
6. What medication (dose and frequency) is the patient taking?
7. Is this symptom a recent change?
8. How many times a day is flatus passed?
Physical assessment will determine the presence or absence of bowel sounds,
flatus, or abdominal distention. Patients with colostomies should also be
assessed for constipation. Dietary habits, fluid intake, activity levels, and
use of opioids in these patients should be assessed. Irrigation of the
colostomy should be monitored for proper technique.
-- Management of constipation --
Comprehensive management of constipation includes prevention (if possible),
elimination of causative factors, and judicious use of laxatives. Some
patients can be encouraged to increase dietary fiber (fruits; green, leafy
vegetables; whole grain cereals; breads; and bran) and to increase fluid intake
to one-half ounce per pound of body weight daily (if not contraindicated by
renal or heart disease). A study that involved geriatric patients compared the
efficacy, cost, and ease of administration of a natural laxative mixture
(raisins, currants, prunes, figs, dates, and prune concentrate) with protocols
using stool softeners, lactulose, and other laxatives. Results indicate lower
costs, more natural and regular bowel movements, and increased ease of
administration with natural laxatives. Even though generalization from these
findings is limited by small sample size, additional exploration of natural
laxatives in cancer patient populations might be useful.[4] A program for
prevention of constipation in cancer patients is described below.
Goal: Prevention of constipation with evacuation of at least one soft stool
daily.
Assessment:
1. Establish the patient's normal bowel pattern and habits (time of day for
normal bowel movement, consistency, color, and amount).
2. Explore the patient's level of understanding and compliance relating to
exercise level, mobility, and diet (fluid, fruit, and fiber intake).
3. Determine normal or usual use of laxatives, stimulants, or enemas.
4. Determine laboratory values, specifically looking at platelet count.
5. Conduct a physical assessment of the rectum (or stoma) to rule out
impaction.
Commonly used interventions include (record bowel movements daily):
- Encourage patient to increase fluid intake, with a goal of drinking eight
8-ounce (150-200 mL) glasses of fluid daily unless contraindicated.
- Encourage regular exercise, including abdominal exercises in bed or moving
from bed to chair if the patient is not ambulatory.
- Experts recommend that healthy adults consume between 20 to 35 grams of
fiber per day (average consumption is 11 grams). While there are no
specific fiber recommendations for cancer patients, they should also be
encouraged to eat more high-fiber foods such as fruits (e.g., raisins,
prunes, peaches, and apples), vegetables (e.g., squash, broccoli, carrots,
and celery), and whole grain cereals, breads, and bran. Increased fiber
intake must be accompanied by increased fluid intake or constipation may
result. High fiber intake is contraindicated in patients at increased
risk for bowel obstruction such as those with a history of bowel
obstruction or status postcolostomy.
- Provide a warm or hot drink approximately one-half hour before time of
patient's usual defecation.
- Provide privacy and quiet time at the patient's usual or planned time for
defecation.
- Provide toilet or bedside commode and appropriate assistive devices; avoid
bedpan-use whenever possible.
- Start one of the following regimens if the patient has not had a stool in
3 days or on the first day that any patient starts taking drugs associated
with constipation:
stool softeners (e.g., docusate sodium, 1-2 capsules per day). For
opioid-related constipation, stool softeners should be used in combination
with a stimulant laxative. Bulk producing agents are not recommended for
use in a regimen used to counteract the bowel effects of opioids.
2 tablets of a senna preparation twice daily.
5 mL of cascara at bedtime.
1 bisacodyl tablet at bedtime.
milk of magnesia, 30 to 45 mL if a bowel movement is not achieved in 24
hours after other methods are instituted.
- If the amount of stool is still inadequate, increase stool softeners up
to 6 capsules per day or a senna preparation (e.g., Senokot) gradually to
a maximum of 8 tablets (4 tablets twice a day); cascara may be increased
gradually to 10 mL; bisacodyl may be increased gradually to 3 tablets.
Add milk of magnesia to cascara.
- If the amount of stool is still inadequate, a glycerin or bisacodyl
suppository or enema (phosphate/biphosphate, oil retention, or tap water)
should be used with caution, especially in patients with neutropenia or
thrombocytopenia.
Medical management includes the administration of saline or chemical laxatives,
suppositories, enemas, or agents that increase bulk.
Rectal agents should be avoided in cancer patients at risk for
thrombocytopenia, leukopenia, and/or mucositis from cancer and its treatment.
In the immunocompromised patient, no manipulation of the anus should occur,
i.e., no rectal examinations, no suppositories, and no enemas. These actions
can lead to the development of anal fissures or abscesses, which are portals of
entry for infection. Also, the stoma of a patient with neutropenia should not
be manipulated.
-- Medical agents for constipation --
===============================================================================
-------------------------------------------------------------------------------
Bulk producers
Bulk producers are natural or semisynthetic polysaccharide and cellulose. They
work with the body's natural processes to hold water in the intestinal tract,
soften the stool, and increase the frequency of the passage of stool. Bulk
producers are not recommended for use in a regimen to counteract the bowel
effects of opioids.
Onset: 12 to 24 hours (may be delayed up to 72 hours)
Caution: Take with 2 full 8-oz (150-200 mL) glasses of water and maintain
adequate hydration to avoid the risk of developing a bowel
obstruction. Avoid administering psyllium with salicylates,
nitrofurantoin, and digitalis because psyllium decreases the actions
of these drugs. Avoid use if intestinal obstruction is suspected.
Use: Effective in managing irritable bowel syndrome.
Drugs and dosages:
methylcellulose: 5 to 20 cc 3 times per day with water
(Cologel)
barley malt extract: 4 tablets with meals and at bedtime or 2 T powder or
(Maltsupex) liquid 2 times per day for 3 to 4 days, then 1 to 2 T
at bedtime
psyllium: varies from 1 T to 1 packet, depending on brand, 1 to
3 times per day
Fiber-Malt: 1 T 2 or 3 times daily; 1 to 3 times daily for
children 4 to 12 years of age; not to be given to
children younger than 4 years of age
(T = tablespoonful)
------------------------------------------------------------------------------
Saline laxatives
The high osmolarity of the compounds in saline laxatives attracts water into
the lumen of the intestines. The fluid accumulation alters the stool
consistency, distends the bowel, and induces peristaltic movement. Cramps may
occur.
Onset: 0.5 to 3 hours
Caution: Repeated use can alter fluid and electrolyte balance. Avoid
magnesium-containing laxatives in patients with renal dysfunction.
Avoid sodium-containing laxatives in patients with edema, congestive
heart failure, megacolon, or hypertension.
Use: Used mostly as a bowel preparation to clear the bowels for rectal
or bowel examinations.
Drugs and dosages:
magnesium sulfate: 15 g in a glass of water
milk of magnesia: 10 to 20 cc if concentrated, 15 to 30 cc if regular
magnesium citrate: 240 cc
sodium phosphate: 4 to 8 g dissolved in water
mono- and di-basic
sodium phosphate: 20 to 40 mL mixed with 4 oz cold water
(Fleet Phospho-soda)
------------------------------------------------------------------------------
Stimulant laxatives
Stimulant laxatives increase motor activity of the bowels by direct action on
the intestines.
Onset: 6 to 10 hours
Caution: Prolonged use of these drugs causes laxative dependency and loss of
normal bowel function. Prolonged use of cascara and danthrum
discolors rectal mucosa and discolors alkaline urine red. Bisacodyl
must be excreted in bile to be active and are not effective with
biliary obstruction or diversion. Avoid bisacodyl with known or
suspected ulcerative lesions of the colon. These medications may
cause cramping.
Drug interactions:
Avoid taking bisacodyl within 1 hour of taking antacids, milk, or
cimetidine because they cause premature dissolving of the enteric
coating, which results in gastric or duodenal stimulation. There
is an increased absorption of danthron when it is given with
docusate.
Use: Used to evacuate bowel for rectal or bowel examinations. Most of
the stimulant laxatives act on the colon.
Drugs and dosages:
cascara sagrada: tablet (325-650 mg); fluid extract (1 cc); aromatic fluid
extract (5 cc)
danthron: 37.5 to 150 mg with or 1 hour after evening meal
calcium salts
of sennosides: 12 to 24 mg at bedtime
senna: Senolax, Seneson, or Black-Draught (2 tablets); Senokot
(2 tablets or 10-15 cc at bedtime); Casafru (5 cc)
bisacodyl: 10 to 15 mg swallowed whole, not chewed, or 10 mg
suppository
-------------------------------------------------------------------------------
Lubricant laxatives
Lubricant laxatives lubricate intestinal mucosa and soften stool.
Caution: Administer on empty stomach at bedtime. Mineral oil prevents
absorption of oil-soluble vitamins and drugs. With elderly
patients, aspiration potential suggests that mineral oil should be
avoided because it can cause lipid pneumonitis. It can interfere
with postoperative healing of anorectal surgery. Avoid giving with
docusate sodium. Docusate sodium causes increased systemic
absorption of mineral oil.
Use: Used prophylactically to prevent straining in patients for whom it
would be dangerous to strain.
Drugs and dosages:
mineral oil: 5 to 30 cc at bedtime
------------------------------------------------------------------------------
Fecal softeners
Fecal softeners promote water retention in the fecal mass, thus softening the
stool. Up to 3 days may pass before an effect is noted. Stool softeners and
emollient laxatives are of limited use because of colonic resorption of water
from the forming stool.
Fecal softeners should not be used as the sole regimen but may be useful given
in combination with stimulant laxatives.
Caution: May increase the systemic absorption of mineral oil when administered
together.
Use: Used prophylactically to prevent straining. Most beneficial when
stool is hard.
Drugs and dosages:
docusate sodium: 50 to 240 mg taken with a full glass of water
docusate calcium: 240 mg each day until bowel movement is normal
docusate potassium: 100 to 300 mg each day until bowel movement is
normal; should increase daily fluid intake
Polaxer: 188 mg (480 mg at bedtime)
------------------------------------------------------------------------------
Lactulose (Cholac, Cephulac)
Lactulose is a synthetic disaccharide that passes to the colon undigested.
When it is broken down in the colon, it produces lactic acid, formic acid,
acetic acid, and carbon dioxide. These products increase the osmotic pressure,
thus increasing the amount of water held in the stool, which softens the stool
and increases the frequency of passage.
Onset: 24 to 48 hours
Caution: Excessive amounts may cause diarrhea with electrolyte losses.
Avoid giving with acute abdomen, fecal impaction, or obstruction.
Dosage: 15 to 30 cc each day (contains 10-20 g of lactulose).
Polyethylene glycol and electrolytes (Golytely, Colyte)
Five packets are mixed with 1 gallon (3.785 liters) of tap water and contain
the following: polyethylene glycol (227.1 g), sodium chloride (5.53 g),
potassium chloride (2.82 g), sodium bicarbonate (6.36 g), and sodium sulfate
(anhydrous) (21.5 g). Do not add flavorings. Serve chilled to improve
palatability. Can be stored up to 48 hours in the refrigerator.
Use: Used to clear bowel with minimal water and sodium loss or gain.
-------------------------------------------------------------------------------
===============================================================================
References:
1. Portenoy RK: Constipation in the cancer patient: causes and management.
Medical Clinics of North America 71(2): 303-311, 1987.
2. McShane RE, McLane AM: Constipation: consensual and empirical validation.
Nursing Clinics of North America 20(4): 801-808, 1985.
3. Bruera E, Suarez-Almazor M, Velasco A, et al.: The assessment of
constipation in terminal cancer patients admitted to a palliative care
unit: a retrospective review. Journal of Pain and Symptom Management
9(8): 515-519, 1994.
4. Beverley L, Travis I: Constipation: proposed natural laxative mixtures.
Journal of Gerontological Nursing 18(16): 5-12, 1992.
** IMPACTION **
-- Causes of impaction --
Five major factors precipitate impaction: opioid analgesics, prolonged
inactivity, dietary alterations, psychiatric illness, and ironically, chronic
use of drugs for constipation.[1] Laxatives used to decrease constipation are
the drugs that contribute most to the development of constipation and
impaction. Repeated and escalating dosing of laxatives renders the colon less
sensitive to its intrinsic reflexes stimulated by distention. (Refer to the
Constipation section for causes of constipation and impaction.)
-- Signs and symptoms of impaction --
The patient may exhibit symptoms similar to constipation or present with
symptoms unrelated to the gastrointestinal system. If the impaction presses on
the sacral nerves, the patient may experience back pain. If the impaction
presses on the ureters, bladder, or urethra, urinary symptoms can develop.
These symptoms include increased or decreased frequency or urgency of
urination, or urinary retention.
When abdominal distention occurs, movement of the diaphragm is compromised,
leading to insufficient aeration with subsequent hypoxia and left ventricular
dysfunction. Hypoxia can, in turn, precipitate angina or tachycardia. If the
vaso-vagal response is stimulated by the pressure of impaction, the patient may
become dizzy and hypotensive.
Movement of stool around the impaction may result in diarrhea, which can be
explosive. Coughing or activities that increase intra-abdominal pressure may
cause leakage of stool. The leakage may be accompanied by nausea, vomiting,
abdominal pain, and dehydration and is virtually diagnostic of the condition.
Thus, the patient with an impaction may present in an acutely confused and
disoriented state, with signs of tachycardia, diaphoresis, fever, elevated or
low blood pressure, and/or abdominal fullness or rigidity.
-- Assessment of impaction --
Assessment includes the questions discussed previously for the patient with
constipation (Refer to the Constipation section of this summary). Additional
assessment includes auscultation of bowel sounds to determine if they are
present, absent, hyperactive, or hypoactive. The abdomen should be inspected
for distention and gently palpated for any masses, rigidity, or tenderness. A
rectal examination will determine the presence of stool in the rectum or
sigmoid. An abdominal x-ray (flat and upright) would show loss of haustral
markings, gas patterns reflecting gross amounts of stool, and dilatation
proximal to the impaction.[2]
If a diagnosis of fecal impaction is uncertain, a laboratory work-up can rule
out other problems. A complete blood cell count, appropriate blood
chemistries, chest x-ray, and an electrocardiogram can be performed. If the
patient has become dehydrated, the blood urea nitrogen, creatinine, and serum
osmolality will be elevated. There may be an elevation of the hemoglobin and
hematocrit indicating hemoconcentration. The white blood cell count (WBC) may
be slightly elevated in the presence of a fever. If the WBC count is extremely
elevated and the patient is exhibiting a high fever and abdominal pain, an
obstruction, perforation, infection, or inflammatory process must be ruled out.
With marked distention of the cecum (12 cm diameter or more), there is a risk
of bowel perforation.
-- Treatment of impaction --
The primary treatment of impaction is to hydrate and soften the stool so that
it can be removed or passed. Enemas, either oil retention, tap water, or
hypertonic phosphate, lubricate the bowel and soften the stool. Caution must
be exercised; fecal impaction can irritate the bowel wall and enemas in excess
may perforate the bowel. The patient may need to be digitally disimpacted if
the stool is within reach. This is best done after administering an enema to
lubricate the bowel.
Nonstimulating bowel softeners, such as docusate, can be used to help soften
stool higher in the colon. Mineral or olive oil can be given to loosen the
stool. Caution should be used when giving docusate sodium with mineral oil
because there could be an increased systemic absorption of the mineral oil
leading to systemic lipid granulomas.[3] Glycerin suppositories can also be
used. Any laxatives that might stimulate the bowel or cause cramping should be
avoided so that the bowel is not damaged further.
References:
1. Cefalu CA, McKnight GT, Pike JI: Treating impaction: a practical approach
to an unpleasant problem. Geriatrics 36(5): 143-146, 1981.
2. Bruera E, Suarez-Almazor M, Velasco A, et al.: The assessment of
constipation in terminal cancer patients admitted to a palliative care
unit: a retrospective review. Journal of Pain and Symptom Management
9(8): 515-519, 1994.
3. Brandt LJ: Gastrointestinal Disorders of the Elderly. New York: Raven
Press, 1984.
** LARGE OR SMALL BOWEL OBSTRUCTION **
There are 4 types of obstruction: simple, closed-loop, strangulated, and
incarcerated. A simple obstruction is blocked in one place, whereas a
closed-loop is blocked in two places. A closed-loop obstruction may develop
when the bowel twists around on itself, isolating the looped section of the
bowel and obstructing the portion above it. With a strangulated obstruction,
there is decreased blood flow to the bowel that, if not relieved, will develop
into an incarcerated obstruction and the bowel will become necrotic.
The obstructing mechanism can be mechanical or nonmechanical. Mechanical
factors can be anything that causes a narrowing of the intestinal lumen (e.g.,
inflammation or trauma to the bowel, neoplasms, adhesions, hernias, volvulus,
or a compression from outside the intestinal tract).[1] Nonmechanical factors
include those that interfere with the muscle action or innervation of the
bowel: paralytic ileus, mesenteric embolus or thrombus, and hypokalemia.
Eighty percent of bowel obstructions occur in the small intestine; the other
20% occur in the colon.[2] Bowel obstructions are frequently seen in the
ileum. Small bowel obstructions are caused frequently by adhesions or hernias,
whereas large bowel obstructions are caused commonly by carcinomas, volvulus,
or diverticulitis. The presentation of obstruction will relate to whether the
small or large intestine is involved.
-- Etiology of bowel obstruction --
The most common malignancies that cause bowel obstruction are cancers of the
colon, stomach, and ovary. Extra-abdominal cancers (such as lung and breast
cancers and melanoma) can spread to the abdomen, causing bowel obstruction.[3]
Patients who have had abdominal surgery or abdominal radiation are also at
higher risk of developing bowel obstruction.[2] Bowel obstructions are most
common during advanced stages of disease.
-- Assessment and diagnosis of bowel obstruction --
Examination of the patient will determine the presence or absence of abdominal
pain or vomiting, and evidence of the passage of flatus or stool. A complete
blood cell count, electrolyte panel, and urinalysis are obtained to evaluate
fluid and electrolyte imbalance and/or sepsis. An elevated white blood cell
count (15,000-20,000 cells per cubic millimeter) suggests bowel necrosis. Flat
and upright abdominal films as well as a barium enema may be necessary to
determine where the obstruction is located. While it remains controversial, an
upper gastrointestinal series is contraindicated with an acutely presenting
obstruction because it can cause a partial obstruction to become complete or
may further complicate a total obstruction. If the patient is exhibiting
dehydration, oliguria, or shock, perforation of the bowel may have occurred,
and immediate medical or surgical intervention is indicated. (Refer to the
Nausea, Vomiting, Constipation, and Bowel Obstruction in Advanced Cancer
section in the PDQ summary on Nausea and Vomiting.)
-- Treatment of acute bowel obstruction --
Careful serial examinations are necessary in the management of patients with
progressive abdominal symptoms that may be due to acute bowel obstruction. The
principles of supportive care in this setting include volume resuscitation,
correction of electrolyte imbalances, and transfusion support (if necessary).
These measures should precede or accompany decompression efforts.
When bowel obstruction is partial, decompression of the distended bowel may be
attempted with nasogastric or intestinal tubes. Although use of these tubes
may be successful in reducing edema, relieving fluid and gas accumulation, or
decreasing the need for multiple stage procedures,[4] surgery may be necessary
within 24 hours if there is complete, acute obstruction.
-- Management of chronic, malignant bowel obstruction --
Patients with advanced cancer may have chronic, progressive bowel obstruction
that is inoperable. The most frequent causes of inoperability are extensive
tumor and multiple partial obstructions.[5-7] In some instances, an expandable
metal stent may be feasible. These stents are made of metal alloys and are
placed under endoscopic guidance with the aid of fluoroscopy. Esophageal,
biliary, gastroduodenal, and colorectal stents have been described.[8-11]
In situations where neither surgery nor stenting is possible, the accumulation
of the unabsorbed secretions produce nausea, vomiting, pain and colicky
activity as a consequence of the partial or complete occlusion of the lumen.
In this case, a gastrostomy tube is commonly used to provide decompression of
air and fluid that may be accumulating and causing visceral distention and
pain. Such a tube is placed into the stomach and is attached to a drainage bag
with the apparatus easily concealed under clothing. When the valve between the
gastrostomy tube and the bag is open, the patient may be able to eat or drink
by mouth without creating discomfort since the food is drained directly into
the bag. Dietary discretion is advised to minimize the risk of tube
obstruction by solid food. If the obstruction improves, the valve can be
closed and the patient may once again benefit from enteral nutrition.
Sometimes, decompression is difficult even with a gastrostomy tube in place.
This may be due to the accumulation of fluid, since several liters per day of
gastrointestinal secretions may be produced. To relieve continuous abdominal
pain, opioid analgesics via continuous subcutaneous or intravenous infusion may
be necessary. Effective antispasmodics in this situation include
anticholinergics (such as hyoscine butylbromide) [12] and possibly
corticosteriods as well as centrally acting agents. If the bowel obstruction
is thought to be functional (rather than mechanical) in origin, metoclopramide
is the drug of choice due to its prokinetic effects on the bowel. For complete
bowel obstruction thought to be irreversible, a trial of an antispasmodic such
as hyoscyamine may decrease bowel contractions and therefore, yield pain
relief. Another option for management of refractory pain and/or nausea is the
synthetic somatostatin-analogue octreotide. This agent inhibits the release of
several gastrointestinal hormones and reduces gastrointestinal
secretions.[13,14] Octreotide is usually given subcutaneously at 50 to 200 mcg
three times per day.[8,15-17] Corticosteriods are widely used in treating
bowel obstruction but empirical support is limited.[18] They may be useful as
adjuvant antiemetics and analgesics in this setting given as dexamethasone at a
starting dose of 6 to 10 mg subcutaneously or intravenously 3 to 4 times per
day.[8,15] (Refer to the Nausea, Vomiting, Constipation, and Bowel Obstruction
in Advanced Cancer section in the PDQ summary on Nausea and Vomiting.)
References:
1. Givens BA, Simmons SJ: Gastroenterology in Clinical Nursing. St. Louis,
MO: C.V. Mosby Co, 4th ed., 1984.
2. Bouchier IA: Gastroenterology. London: Balliere Tindall, 3rd ed., 1982.
3. Ripamonti C, De Conno F, Ventafridda V, et al.: Management of bowel
obstruction in advanced and terminal cancer patients. Annals of
Oncology 4(1): 15-21, 1993.
4. Horiuchi A, Maeyama H, Ochi Y, et al.: Usefulness of Dennis Colorectal
Tube in endoscopic decompression of acute, malignant colonic
obstruction. Gastrointestinal Endoscopy 54(2): 229-232, 2001.
5. Jung GS, Song HY, Kang SG, et al.: Malignant gastroduodenal obstructions:
treatment by means of a covered expandable metallic stent-initial
experience. Radiology 216(3): 758-763, 2000.
6. Camunez F, Echenagusia A, Simo G, et al.: Malignant colorectal
obstruction treated by means of self-expanding metallic stents:
effectiveness before surgery and in palliation. Radiology 216(2):
492-497, 2000.
7. Coco C, Cogliandolo S, Riccioni ME, et al.: Use of a self-expanding stent
in the palliation of rectal cancer recurrences. A report of three cases.
Surgical Endoscopy 14(8): 708-711, 2000.
8. Baron TH: Expandable metal stents for the treatment of cancerous
obstruction of the gastrointestinal tract. New England Journal of
Medicine 344(22): 1681-1687, 2001.
9. Law WL, Chu KW, Ho JW, et al.: Self-expanding metallic stent in the
treatment of colonic obstruction caused by advanced malignancies.
Diseases of the Colon and Rectum 43(11): 1522-1527, 2000.
10. Repici A, Reggio D, De Angelis C, et al.: Covered metal stents for
management of inoperable malignant colorectal strictures.
Gastrointestinal Endoscopy 52(6): 735-740, 2000.
11. Harris GJ, Senagore AJ, Lavery IC, et al.: The management of neoplastic
colorectal obstruction with colonic endolumenal stenting devices.
American Journal of Surgery 181(6): 499-506, 2001.
12. De Conno F, Caraceni A, Zecca E, et al.: Continuous subcutaneous infusion
of hyoscine butylbromide reduces secretions in patients with
gastrointestinal obstruction. Journal of Pain and Symptom Management
6(8): 484-486, 1991.
13. Ripamonti C, Mercadante S, Groff L, et al.: Role of octreotide,
scopolamine butylbromide, and hydration in symptom control of patients
with inoperable bowel obstruction and nasogastric tubes: a prospective
randomized trial. Journal of Pain and Symptom Management 19(1): 23-34,
2000.
14. Fallon MT: The physiology of somatostatin and its synthetic analogue,
octreotide. European Journal of Palliative Care 1(1): 20-22, 1994.
15. Mercadante S: Assessment and management of mechanical bowel obstruction.
In: Portenoy RK, Bruera E, eds.: Topics in Palliative Care. Volume 1.
New York, NY: Oxford University Press, 1997, pp 113-130.
16. Fainsinger RL: Integrating medical and surgical treatments in
gastrointestinal, genitourinary, and biliary obstruction in patients
with cancer. Hematology/Oncology Clinics of North America 10(1):
173-188, 1996.
17. Ripamonti C, Panzeri C, Groff L, et al.: The role of somatostatin and
octreotide in bowel obstruction: pre-clinical and clinical results.
Tumori 87(1): 1-9, 2001.
18. Feuer DJ, Broadley KE: Systematic review and meta-analysis of
corticosteroids for the resolution of malignant bowel obstruction in
advanced gynaecological and gastrointestinal cancers. Systematic Review
Steering Committee. Annals of Oncology 10(9): 1035-1041, 1999.
Date Last Modified: 09/2002
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