or fluid bowel movements), occurs in about 5% of hospice patients.
2mg to 4mg every 6 hours acts locally on the gut and is usually more
useful than the centrally acting opioids (morphine, codeine,
diphenoxylate) because the patient is often already taking opioids.
Loperamide should also be available if drugs that can cause diarrhea
The most common causes of diarrhea are:
intestinal obstruction (dysfunction)
imbalance or drugs
(discharge plus blood)
impaction is commonly seen in patients on opioids who have been
given laxatives either too late or in too low a dosage. It can often
be diagnosed from the history. There are no bowel movements for
several days, and then there is passage of small amounts of liquid
feces, sometimes without control. Rectal examination reveals a large,
clay-like lump of feces which usually has to be removed by manual
evacuation under sedation. Occasionally the rectum is ballooned and
empty, and the impaction has occurred higher up (palpable abdominally
or visible on plain abdominal x-ray). The patient may require
in-patient admission to clear this sort of constipation. (see
means loose, pale, foul-smelling feces. (Relatives sometimes fear they
contain cancer.) Steatorrhea can be missed without a good history. The
patient usually complains simply of diarrhea, but steatorrhea does not
respond to anti-diarrheal drugs. It is due to malabsorption of fat,
and is most commonly seen in patients with carcinoma of the pancreas.
The patient usually has bowel movements four or five times a day, with
large quantities of feces that tend to float, and are difficult to
flush away in the toilet. Steatorrhea responds to pancreatic enzyme
replacement tablets containing all major pancreatic enzymes: lipase,
protease and amylase.
The enzymes are
destroyed by gastric acid and therefore tablets are best taken
immediately before a meal or a snack, or with milk. (The required dose
may be 2 to 10 tablets or more, depending on the strength of the
pancreatic replacement used.) The dosage is adjusted according to the
frequency of bowel movements. Excessive dosage may irritate the skin
around the anus. Resistant steatorrhea may further respond by giving
cimetidine 200mg, 30 minutes before the meal, to reduce gastric acid
secretion. Measurement of fecal fats by the laboratory is unnecessary:
the clinical picture is usually obvious once considered.
intestinal obstruction is usually seen with carcinoma of the ovary
(25% develop obstruction) or carcinoma of the colon or rectum. In
reality, it is often malignant intestinal “dysfunction” rather than
“obstruction” because bowel disturbances are often intermittent and
can either cause constipation or diarrhea. (see
Diarrhea in this
situation is best treated with loperamide 2mg to 4mg every 6 hours
(care being taken to stop it after the diarrhea has settled, to avoid
constipation). Diarrhea due to malignant intestinal dysfunction can
respond to high dose steroids (dexamethasone 8mg per day).
malignant ileo-colic fistula causes a short circuit of the bowel.
Diarrhea can then be worsened by retrograde bacterial overgrowth in
the small intestine (which is normally sterile) with deconjugation of
bile salts and malabsorption of fat. This can respond to oral
tetracycline 500mg every 6 hours.
imbalance – The incorrect use of laxatives can cause diarrhea. If
the patient is on opioid analgesics it is essential to take laxatives
daily. Usually there has been under-use of laxatives in a patient on
opioids which has allowed constipation to develop. Excessive laxatives
are then taken to clear the constipation and hard feces are finally
passed, followed (sometimes explosively) by soft feces.
that can cause diarrhea include antibiotics, antacids with magnesium
salts, NSAIDs and antifibrinolytic drugs. Oral phosphate used to treat
hypercalcemia causes severe diarrhea. Chemotherapy (especially with
mitomycin or fluorouracil) can cause diarrhea.
– Mucous discharge or bleeding from carcinoma of the rectum can be
treated by radiotherapy. A palliative colostomy does not relieve these
local symptoms. Hydrocortisone foam, one applicator-full 2 times a
day, can be helpful, as can oral steroids (dexamethasone 8mg 2 times a
day). Profuse mucous diarrhea can cause hypokalemia. Laser therapy via
an endoscope can be very successful in reducing bleeding and discharge
from carcinoma of the rectum, and it can also improve the patency of
the lumen and prevent obstruction. It usually needs to be repeated.
The discharge can be foul-smelling and metronidazole (500mg every 8
hours) usually reduces the smell. (see Lasers)
(methylcellulose tablets or granules) can help control diarrhea due to
rectal tumors, by establishing a bowel routine. They take 2 or 3 days
to take effect, and dose is tailored to effect.
incontinence due to loss of sphincter control – There may be
perineal numbness, usually as part of spinal cord compression syndrome
with paraplegia. It is usually best managed by reducing or stopping
laxatives and giving daily or alternate-day manual evacuations. (see
Spinal Cord Compression)
incontinence may be due to a recto-vaginal fistula, and the
patient may be too embarrassed to complain that feces are leaking from
her vagina. A palliative colostomy should always be considered for
this distressing condition. (see Fistulas)
tumors are slow-growing tumors of the small intestine (less
commonly bronchus, large bowel or pancreas) which can secrete 5HT
These symptoms do
not occur if blood from the tumor passes through a normal liver, so
these tumors only produce symptoms once liver metastases have
occurred. (Bronchial carcinoids are often metabolically inactive.) The
primary tumor usually remains small but massive hepatomegaly
eventually occurs. It is occasionally possible to block the metabolic
effects with drugs, but treatment may fail because tumors can produce
more than one active agent.
Diarrhea can be
profuse (1 liter per day) and may not respond to anti-diarrheals. If
the terminal ileum has been resected diarrhea may be due to excess
bile salts, and cholestyramine can help. If it is due to 5HT, 5HT
antagonists may help, either cyproheptadine 4mg to 8mg 4 times a day,
or methysergide 1 mg at bedtime increasing to 1 mg to 2mg 3 times a
day. Bulking of the feces (with methylcellulose) can reduce the
frequency of diarrhea and establish a bowel routine.
The author and publisher have taken
precautions to ensure that the information in this book is
error-free. However, readers must be guided by their own
personal and professional standards of good practice in
evaluating and applying recommendations made herein. The
contents of this book represent the views and experience of
the author, and not necessarily those of the publisher.