Contents
Definition of diarrhea
Acute vs. chronic diarrhea
Scope of the problem
The child with acute diarrhea: Care at home, or medical care?
Causes of acute diarrhea in children
Acute diarrhea in children: Principles of management
Medical tests in the child with acute diarrhea
Rehydration of the child with acute diarrhea
Oral rehydration therapy: Rationale and composition
Evaluation and management of the adult with acute diarrhea
Definition of diarrhea
Diarrhea is a condition characterized by increased frequency and liquidity of bowel movements.1, 2 Patients usually do not refer to frequent non-liquid bowel movements as “diarrhea,” but they may refer to even a single loose stool as “diarrhea.”
Three bowel movements per day are
generally considered the upper end of normal stool output. The
traditional scientific definition of diarrhea emphasizes the weight of stool,
with >200 grams/day being considered “diarrhea.”2 However,
most of the time it is not practical to actually measure stool output. Some
individuals on high fiber diets can have normal, non-liquid stool output of up
to 300 grams/day.
Acute vs. chronic diarrhea
Diarrhea
can be acute or chronic. “Acute diarrhea” is defined as an episode
of diarrhea that lasts 14 days or less.3 Diarrhea that
lasts for more than 14 days is considered “persistent,”3 but
not all cases of persistent diarrhea last for months or more, or are associated
with an underlying chronic disease. Diarrhea that lasts for 4 weeks
or more is considered “chronic.”1, 3
The
approaches to acute vs. chronic diarrhea differ substantially,
in large part because of the different possible causes and complications of
acute vs. chronic diarrhea. Acute diarrhea is
generally due to an infection (“acute gastroenteritis,” which can have many
causes including viruses and bacteria), and it is self-limited by
definition. Chronic diarrhea can be caused by multiple
diseases. The specific disease determines the characteristics and patterns
of the diarrhea.
Scope of the problem
Diarrhea is extremely common. Most cases of diarrhea do not come to medical attention. Although acute diarrhea is self-limited, it can be severe and can lead to profound dehydration (low fluid level in the body, which can lead to abnormally low blood volume, low blood pressure, and damage to the kidneys, heart, liver, brain, heart, and other major organs). For this reason, acute
diarrhea remains a major cause of infant mortality around the world. Over 2 million deaths are attributed to acute diarrhea every year world-wide, most of them in the developing world.4-6 In the United States, up to 375 million episodes of acute diarrhea occur every year, leading to nearly 1 million hospitalizations and 6,000 deaths.6 Chronic diarrhea can cause significant disability. It is estimated that in the United States 5% of adults have chronic diarrhea.7
The child with acute diarrhea: Care at home, or medical care?
Care
of the child with diarrhea usually begins at home, but caregivers may not
always be able to recognize severe dehydration and may not always be able to
provide oral rehydration (replenishment of water and salts by
mouth). Several guidelines have been proposed for the management of
acute diarrhea in children.4, 8 Most children with acute
diarrhea do not have a life-threatening illness, but the first step is to
assess whether the child is dangerously ill and/or severely dehydrated, and to
consider the possibility of serious underlying disease.
It is recommended that medical care for acute diarrhea be sought whenever an infant appears to be in distress, because infants can become severely dehydrated rather quickly.4 The indications for medical evaluation of children with acute diarrhea include:4
· Age
less than 6 months or weight less than 8 kg (17.6 pounds)
· History
of premature birth; chronic or concurrent medical conditions
· Fever
≥38ºC (100.4ºF) for age <3 months, or ≥39ºC (102.2ºF) for ages 3-36 months
· Blood
in stool
· High
output (frequent and substantial volume) of diarrhea
· Persistent
vomiting
· Signs
of dehydration (sunken eyes, dry mouth, decreased urine)
· Irritability,
apathy, lethargy
· Suboptimal
response to oral rehydration at home, or inability to provide oral rehydration
therapy at home
Children
who are most ill may require admission to the hospital. Hospital
inpatient care is indicated for children if:4
· Caregivers
cannot provide adequate care at home
· Substantial
difficulties exist in administrating oral rehydration therapy (intractable
vomiting, oral rehydration solution refusal or inadequate intake)
· Other
possible illnesses complicate the clinical course
· Oral
rehydration solution treatment fails, including worsening diarrhea or
dehydration despite adequate volumes
· Severe
dehydration (>9% of body weight) exists
· Social
or logistical concerns exist that might prevent return for further evaluation,
if necessary
· There
is a need for close observation (young age, unusual irritability or drowsiness,
progressive course of symptoms, or uncertainty of diagnosis)
Causes of acute diarrhea in children
A
wide range of problems4, 8 can present with acute diarrhea in a
child, including gastrointestinal infections, most commonly viral, but also
bacterial and parasitic; non-gastrointestinal infections, such as meningitis,
bacterial sepsis, ear, lung, or urinary infections, in which vomiting may
predominate; metabolic problems including diabetes, hyperthyroidism (excess of
thyroid hormone), and Addison’s disease (low function of the adrenal glands);
antibiotic-associated diarrhea; constipation with overflow; food allergy or
intolerance; abnormal absorption of nutrients, as in cystic fibrosis and celiac
disease; inflammatory bowel disease (Crohn’s disease or ulcerative colitis);
and irritable bowel syndrome. The latter conditions are more likely
to present with chronic diarrhea.
When
the following signs are present, clinicians should be alerted to look for
causes other than acute viral gastroenteritis:8
· Abdominal
pain with tenderness, with or without guarding (tensing of the abdominal wall
muscles to “protect” the organs from pressure with the examining hand)
· Pale
skin, jaundice (yellow skin), decreased or absent urine output, bloody diarrhea
· Sick-appearing
child out or proportion to the level of dehydration
· Shock
(abnormally low blood pressure with serious associated consequences)
Acute diarrhea in children: Principles of management
The
key principles for appropriate treatment of acute diarrhea in children
emphasize adequate fluid and salt replacement. The principles are:4
· Use
oral rehydration solution
· Oral
rehydration should be performed rapidly (i.e., over a period of 3-4
hours)
· Age-appropriate,
unrestricted diet is recommended as soon as dehydration is corrected
· Nursing
should be continued for breast-fed infants
· Diluted
formula is not recommended and special formulas are not necessary for
formula-fed infants
· Additional
oral rehydration solution should be given to compensate for ongoing losses
· No
unnecessary laboratory tests or medications should be administered
Medical tests in the child with acute diarrhea
Guidelines
suggest that blood tests to measure salts in the blood (electrolytes) and urea
are not necessary in children who are not severely dehydrated or
sick-appearing, and who will receive oral rehydration (see
below). It is recommended that blood tests be performed to measure
urea, creatinine, electrolytes, and bicarbonate in the child with:8
· Severe
dehydration with abnormal circulation
· Moderate
dehydration when a “doughy” feel to the skin may indicate abnormally high
concentration of sodium in the blood (due to the greater loss of water relative
to the loss of sodium)
· Moderate
dehydration when the presentation suggests something other than a
straightforward diarrheal episode
In
children with severe dehydration, blood count and cultures of stool, blood, and
urine are also recommended.8 Stool cultures should also
be obtained in cases of acute bloody diarrhea (dysentery).4
Rehydration of the child with acute diarrhea
The
management of acute diarrhea rests on restoring and maintaining adequate fluid
volume and salt balance (rehydration to correct dehydration, and then
maintenance of hydration to compensate for ongoing losses through diarrhea
and/or vomiting).4, 8 The amount of fluid that a child
has lost is best estimated by the amount of weight loss that the child has
experienced. When weights are not available, the degree of
dehydration can be estimated as mild to moderate (3-9% weight loss) when the
child has, in order of increasing severity: dry mucous membranes in the mouth,
sunken eyes with minimal or no tears, diminished skin turgor (pinched skin in
the abdomen takes 1-2 seconds or more to recoil), drowsiness or irritability,
and deep breathing.4, 8 Dehydration is severe (>9%
weight loss) when the child has increasingly marked signs as described for mild
to moderate dehydration, and also has cool, mottled, pale hands and feet,
fingers that take more than 2 seconds to “pink up again” when squeezed and
released, and, in the extreme, very low blood pressure, rapid heart rate, and
abnormal mental status.4, 8
In
most cases, dehydration can be managed with oral rehydration (by mouth).9,
10 It is estimated that for every 25 children treated with
oral rehydration, one will not respond and will require intravenous hydration
(fluids and electrolytes by vein).10 Oral rehydration
therapy consists of the rehydration phase, in which already lost fluids and
salts are replaced quickly over 3-4 hours, and a maintenance phase, in which
ongoing losses are replaced and nutrition is initiated.4 Families
should start oral rehydration as soon as diarrhea begins, and should provide an
age-appropriate diet, including more frequent breast or bottle feedings for
infants and more fluids for older children.4
In
children with minimal or no dehydration, 1 mL of oral rehydration solution
should ideally be given for each gram of stool output, but stool output cannot
always be measured. In this case, 10 mL/kg body weight can be given
for each watery stool, and 2 mL/kg body weight for each episode of
vomiting. Alternatively, 60-120 mL (2-4 ounces) can be given for
each episode of vomiting or diarrheal stool in children weighing <10 kg
(<22 lbs), and 120-240 mL (4-8 ounces) in children weighing >10
kg. Nutrition should not be restricted.4
In
children with mild to moderate dehydration, their fluid deficit should be
estimated (3-9% of body weight) and should be replaced with a total of 50-100
mL/kg body weight of oral rehydration solution given “little and often” over
3-4 hours.4, 8 This may mean trying 5 mL (1 teaspoon)
every 1-2 minutes with a dropper, syringe, or teaspoon, and increasing the volume
and time interval only if tolerated without vomiting. If rehydration
does not appear to be successful in the first several hours, or if it cannot be
accomplished at home, it should be performed by continuous infusion through a
nasogastric tube (tube placed through the nose into the stomach), or
intravenously.4, 8 After rehydration has been
accomplished, further care can be provided at home if the family understands
and can provide maintenance hydration and continued feeding as described above,
and knows when to return for further medical care (if the child’s condition
does not improve or worsens).4
Severe
dehydration with abnormal circulation is a medical
emergency. Severely dehydrated children should receive 20 mL/kg
intravenous saline to boost the circulation volume quickly, and very ill
children should be admitted to the intensive care unit.4, 8 Additional
fluid may be needed. The blood sodium concentration affects the
recommended rate of rehydration.8 If blood sodium
concentration is not over 150 mEq/L, then oral rehydration can be given over
3-4 hours by mouth or nasogastric tube. If blood sodium
concentration is over 150 mEq/L, then rehydration that is too rapid can be
dangerous, and it is recommended that rehydration be given over 12 hours by
mouth, via nasogastric tube or intravenously, as needed, with monitoring of
blood tests every 2 hours.
Oral rehydration therapy: Rationale and composition
Oral
rehydration therapy is considered one of the great medical innovations of the
20th century.5 Although the current mortality
rate for acute diarrhea is still unacceptably high world-wide, there have been
substantial decreases in mortality rates in recent decades that are attributed
to campaigns promoting oral rehydration therapy.4
The
normal function of the small intestine includes the ability to handle many
liters (in adults, approximately 7 liters) of fluid per day, consisting of
ingested food and water as well as salivary and gastrointestinal
secretions. The small intestine absorbs many liters of fluid with
nutrients and salts and, in adults, it delivers 1-2 liters to the large
intestine (colon), which further absorbs most of this fluid and salts, leading
to normal stool output of <250 mL/day.4 Water
passively follows when sodium (table salt is sodium chloride) is absorbed into
the body, and specialized channels transport sodium and glucose (a sugar)
across the intestinal lining. This co-transport provides the
rationale for oral rehydration solution based on salt, sugar, and water.
In
2002, the World Health Organization recommended an oral rehydration solution
with 75 mmol/L sodium, 75 mmol/L glucose, 20 mmol/L potassium, 65 mmol/L
chloride, 30 mmol/L base and total osmolarity of 245 mOsm/L.4 Commercially
available oral rehydration solutions in the United States include Rehydralyte,
Pedialyte, Endalyte, and CeraLyte, which have similar but not identical
composition to the 2002 World Health Organization oral rehydration solution.4 Many
commercially available beverages, including sports drinks, are used
inappropriately for rehydration. These beverages have very different
compositions from true oral rehydration solutions. They generally
have inadequate salt and sugar content.
It
is possible to make a home-made oral rehydration solution, but because serious
errors can occur, standard commercial oral rehydration solutions are
recommended if available.4 One level teaspoon of table
salt and eight level teaspoons of sugar per liter of water result in a solution
with 86 mmol/L of sodium, and one cup of orange juice or two bananas can be
added for potassium.6
Evaluation and management of the adult with acute diarrhea
Most
cases of acute diarrhea in adults are due to infections, and the same
principles that are outlined for the management of children with acute diarrhea
apply in adults.11 Management in adults is aided by the
fact that dehydration tends not to become severe as quickly as in infants, and
the fact that adults are able to understand their situation and cooperate more
with rehydration. The initial evaluation of adults focuses on
assessing the severity of the illness, the need for rehydration, and the
identification of likely causes and pathogens.6 Clues in
the clinical history include foods eaten, ill contacts, travel, day-care
attendance, and specific clinical symptoms.
Most
diarrheal illnesses in adults are viral or self-limited, and often resolve in
one day.6 For this reason, stool studies are not necessary
in patients who present with a symptom duration of one day, unless they are
severely ill or have bloody diarrhea. Tests for specific pathogens
depend on the details of the clinical presentation.6
As
with children, the cornerstone of therapy is oral rehydration unless the
patient is severely dehydrated or comatose, in which case intravenous
rehydration may be necessary. The World Health Organization oral
rehydration solution, or fluids and salt in soup and crackers are reasonable
treatments.6
Medications in acute diarrhea
Viruses
cause most acute diarrheal illnesses, and most cases of bacterial diarrheal
illnesses are self-limited. Therefore, antibiotics are generally not
necessary or useful. Exceptions exist for immunocompromised hosts,
premature infants, or children with underlying disorders.4 Specific
treatments are recommended for pathogens associated with acute bloody diarrhea
(dysentery) or specific clinical scenarios (e.g., fluoroquinolones for
diarrhea in travelers or in community-acquired cases with fever and severe
disease, and metronidazole for Clostridium difficile infection
or persistent diarrhea with suspected Giardia infection).3, 4, 6
Most
cases of acute diarrhea do not require adjunctive therapy. The
“antidiarrheal” drugs do not treat the underlying causes of
diarrhea. Adsorbents (e.g., kaolin-pectin in Kao-Pectate),
antimotility agents (e.g., loperamide [Imodium], diphenoxylate-atropine
[Lomotil, Lonox]), antisecretory drugs, toxin binders (e.g.,
cholestyramine [Questran]) and bismuth subsalicylate (e.g.,
Pepto-Bismol) are commonly used among older children and adults.4 Because
all of these agents can have side effects and there is no compelling evidence
of benefit in the acute setting, guidelines recommend against the use of
antidiarrheal agents for infants and children with acute gastroenteritis.6,
8
Initial evaluation and management of chronic diarrhea
Chronic
diarrhea has many possible causes, and the evaluation of patients with chronic
diarrhea can be complex and challenging. The clinical history
provides important information in determining the likelihood of different
diagnoses:1, 2
· The
onset, pattern and duration of diarrhea
· Travel,
possibly contaminated food or water, or contact with ill persons
· Watery vs. bloody vs. fatty
stool
· Differentiation
between diarrhea and pure fecal incontinence (leakage of stool)
· Presence
and characteristics of abdominal pain
· Weight
loss
· Factors
that make the diarrhea worse or better (foods, drugs, stress)
· Past
medical and surgical history, and medications
Physical examination primarily helps
determine the volume status of the patient. Rarely, it can point to specific
possible causes of diarrhea.
Blood counts and serum chemistries can
suggest inflammation, blood loss, significant fluid and salt losses, or
malnutrition.1, 12 Serological tests for celiac disease
(a gluten-sensitive enteropathy that is treated with a strict gluten-free diet)
should be considered.
If the initial evaluation suggests an
obvious cause for diarrhea, then management can be instituted, such as stopping
a medication that seems to be causing the diarrhea. Much of the
time, however, further evaluation is necessary.
Possible causes of chronic
diarrhea
The
main causes of chronic diarrhea include chronic infections, inflammatory bowel
disease (Crohn’s disease or ulcerative colitis), microscopic (lymphocytic and
collagenous) colitis, irritable bowel syndrome, maldigestion (abnormal
digestion of nutrients) and malabsorption (abnormal absorption of nutrients),
medication side effects, diabetes, and idiopathic secretory diarrhea (watery
diarrhea of unknown cause, but possibly due to an infection, since this
condition may eventually resolve on its own).2 Less
common causes include malignancy, disorders of metabolism, unusual tumors that
secrete hormones causing diarrhea, previous operations, bacterial overgrowth,
and laxative abuse or factitious diarrhea. The specific setting,
including geographic setting, affects how likely the various diagnoses are,
with chronic infections being more common in developing countries.
Several
classification schemes have been proposed for chronic diarrhea, and these are
not mutually exclusive. They include secretory vs. osmotic
(in osmotic diarrhea, a non-absorbed molecule keeps fluid in the intestine);
small volume (suggestive of colonic disease) vs. large volume
(suggestive of small intestine disease); watery vs. fatty vs. bloody
(bloody stool suggests inflammation or invasive infection, and fatty stool
suggests abnormal digestion or absorption of nutrients).
Consideration
of the clinical details and geographic setting can help determine the type of
diarrhea and the likelihood of the different diagnostic
possibilities. This will help determine the most fruitful sequence
of additional investigations.
Additional tests in patients with chronic diarrhea
Analysis
of the stool can be very informative in chronic diarrhea.1, 2 There
is debate concerning the need to collect stool for 72 hours to quantitate stool
weight and fat content, because collection of a single sample can yield much of
the important information.1, 12 The quantitative
collection can be useful in selected cases.
Measuring
stool serum and potassium concentrations allows calculation of the “osmotic
gap,” which is calculated as 290 – 2([Na+] + [K+])
mOsm/kg. The osmolality of plasma in blood is approximately 290
mOsm/kg, and the intestine cannot affect the concentration of salts in stool in
the same way that the kidney can produce dilute or concentrated
urine. Therefore, the osmolality of stool is comparable to that of
plasma. If the osmotic gap is >125 mOsm/kg, this suggests the
presence of an unabsorbed molecule that is keeping water in the
intestine. Secretory diarrheas have an osmotic gap <50
mOsm/kg. Osmotic diarrhea is usually caused by ingestion of magnesium
(e.g., magnesium hydroxide in milk of magnesia), or malabsorption of
carbohydrate.2, 7
If
stool osmolality is measured, this must be done promptly after stool
collection, because bacterial fermentation will cause the osmolality to rise
with time. Low stool osmolality can occur when stool is mixed with
water or dilute urine, and high osmolality when it is mixed with concentrated
urine. In both of these situations, the stool collection cannot be
considered to be reliable for quantitating volume or calculating the osmolar
gap.
Excess
fat in the stool (steatorrhea, or “fatty diarrhea”) suggests abnormal digestion
(e.g., pancreatic insufficiency) or absorption (e.g., small bowel
mucosal disease). Stool fat excretion of <7 g/day on a 100 g
fat/day diet is considered normal; excretion of 7-14 g/day may be seen simply
as a consequence of increased stool output. However, stool fat
excretion of >14 g/day suggests abnormal digestion or
absorption. Qualitative stool testing for fat may help determine
whether a quantitative collection should be pursued. It is important
for the patient to have adequate fat intake during determination of stool fat
excretion. Patients may learn to avoid fat if it produces oily,
foul, voluminous diarrhea, and testing can be falsely negative if fat is not
being ingested.
Additional
tests on the stool include measuring pH, which can suggest carbohydrate
malabsorption when pH is <5.6 because malabsorbed carbohydrate is
metabolized to fatty acids by colonic bacteria, and looking for fecal
leukocytes (white blood cells) that can suggest the presence of
inflammation.
Further
testing should be tailored to the characteristics of the diarrhea and the
results of the initial tests.1, 2 In patients with
chronic, watery diarrhea with low osmotic gap (secretory diarrhea), the stool
should be tested for pathogens that can cause chronic diarrhea. This
includes three exams for ova and parasites, and a test for Giardia stool
antigen. Testing with Clostridium difficile toxin
assay should be considered, particularly if there is a history of antibiotic
exposure. Bacteria generally do not cause chronic diarrhea,
but Aeromonas andPlesiomonas are
exceptions. Colonoscopy and upper endoscopy with colonic and small
bowel biopsies can help establish the diagnosis of microscopic colitis (in
which the mucosa appears normal endoscopically but shows microscopic
inflammation), or small bowel disease including celiac disease or
giardiasis. Tests for common endocrine conditions including
hyperthyroidism are reasonable. Peptide-secreting tumors are very
rare causes of secretory diarrhea, and serum testing for gastrin, calcitonin,
vasoactive intestinal peptide and somatostatin, and urine measurement of
5-hydroxyindole acetic acid should be done selectively only in persons with
high volume watery diarrhea in whom other tests are
unrevealing. Patients in whom all tests are negative are diagnosed
with idiopathic (“idiopathic” means of unknown origin) secretory
diarrhea. This condition may be due to an unidentified infection and
it can ultimately prove to be self-limited after many months.
In
patients with bloody or inflammatory diarrhea, colonoscopy and small bowel
imaging, if appropriate, should be pursued to evaluate for possible inflammatory
bowel disease, and the low probability of a malignancy causing diarrhea with
blood. Stool culture, Clostridium difficile toxin
assay, and mucosal biopsy may uncover chronic infections.
In
patients with fatty diarrhea, pancreatic or small bowel disease must be
considered. Pancreatic function testing is not widely available, and
its utility is debated. Radiographic studies to rule out pancreatic
structural disease can be considered. The most useful test for
pancreatic exocrine dysfunction, in which not enough digestive enzymes are
produced, is probably to undertake a treatment trial with pancreatic enzyme
supplementation. This should consist of prescribing at least 30,000
units of lipase with every meal, and observing whether the diarrhea
improves. Upper endoscopy with multiple small bowel biopsies is the
principal test for small bowel mucosal disease. Investigations for
bacterial overgrowth include small bowel aspirate with culture and hydrogen
breath testing, but a practical approach is to provide an antibiotic trial and
assess the response.
Treatment of chronic diarrhea
The
treatment of chronic diarrhea depends on the ultimate diagnosis that is made
after pursuing specific tests. Chronic infections are treated with
the appropriate antimicrobials. Celiac disease is managed with a
strict gluten-free diet. Treatment of inflammatory bowel disease can
include 5-aminosalycilates such as sulfasalazine (Azulfidine) or mesalamine
(Asacol, Pentasa), corticosteroids, 6-mercpatopurine or azathioprine,
infliximab (Remicade), and emerging biological agents. Microscopic
colitis may respond to a course of bismuth treatment or to budesonide
(Entocort), or it can be managed with antidiarrheal medications and
5-aminosalycilates. Bacterial overgrowth may require rotating
courses of antibiotics, which can include amoxicillin/clavulanate,
trimethoprim/sulfamethoxazole, doxycycline, metronidazole, and
fluoroquinolones, as well as low-dose injections of octreotide, which may
improve small bowel motility.
Functional
diarrhea and the diarrhea in irritable bowel syndrome can be treated with
antidiarrheals such as loperamide (Imodium) or diphenoxylate/atropine (Lomotil,
Lonox). Idiopathic secretory diarrhea can also be managed with antidiarrheal
medications. Fiber may help firm up the stool.
Some
patients with chronic diarrhea may benefit from treatment with cholestyramine
(Questran), a resin that binds bile acids. Bile acids can stimulate
salt and water secretion in the colon. More potent antidiarrheal
treatment with the opiates codeine, paregoric, and tincture of opium may be
necessary. It must be appreciated that paregoric contains 0.4 mg of
morphine per 1 mL, compared with 10 mg of morphine per 1 mL in tincture of opium,
which is a 25-fold difference.
Special cases: Approach to the traveler with diarrhea, and diarrhea due to Clostridium difficile
Diarrhea
in the traveler requires unique considerations. First, prevention
should be emphasized. Potentially contaminated water and food should be
avoided. Antidiarrheals can be taken to treat diarrhea during
travel, but they are not recommended in the presence of fever or bloody
diarrhea. It is reasonable to carry a fluoroquinolone such as
ciprofloxacin during travel, to be taken if diarrhea with fever or bleeding
develops. Persistent diarrhea in the traveler returning from abroad
presents a broad list of diagnostic possibilities, usually infectious or
post-infectious.13, 14 Stool testing and endoscopic
evaluation with biopsy may be necessary. Specific therapy may be given if
particular pathogens are found, or empiric antimicrobial therapy can be
tried. In cases without a clear cause and without response to
antimicrobial therapy, a post-infectious syndrome is possible, and treatment
can be aimed at the symptom of diarrhea with the antidiarrheal agents described
previously.13
Clostridium
difficile can be responsible for a wide spectrum of disease from
chronic watery diarrhea, to a wasting-type syndrome, to toxic megacolon
representing a medical emergency.15, 16 This bacterium
has been associated traditionally with antibiotic treatment, which allows it to
flourish in the colon while other bacteria are killed and repopulate the colon
less successfully. Clostridium difficile should be
suspected as a possible cause of diarrhea in hospitalized or institutionalized
patients. However, recently it has become clear that
community-acquired Clostridium difficile infection is
increasingly common. First-line treatment should be with oral
metronidazole. Recurrence can be treated with metronidazole again or
oral vancomycin, and subsequent recurrences may require tapered-pulsed
vancomycin with or without cholestyramine or the yeastSaccharomyces
boulardii.17
Conclusion
Diarrhea is extremely common. The causes of acute and chronic diarrhea differ, and this determines the different approach in the acute and chronic setting. Acute diarrhea is usually infectious and self-limited, but it can cause profound dehydration and even death. The cornerstone of management is adequate rehydration to replenish fluid and salt losses that have already occurred, and ongoing hydration to compensate for ongoing losses.
This can usually be accomplished with oral rehydration
solution. Rehydration must be performed with particular
attentiveness in children, who can become dangerously dehydrated more quickly
and easily than adults, and who often cannot cooperate with rehydration as well
as adults. Chronic diarrhea requires a thoughtful approach, with
tests performed in a sequence that is tailored to the specific clinical
presentation. Targeted treatments are available for various causes of
chronic diarrhea. When no specific cause can be uncovered, several medications
are available for symptomatic treatment.