Transcript Acute Diarrhea

Ahmad Hormati
Assistant Professor of Gastroenterology
Qom University of Medical Sciences.
Email: [email protected]
http://hormatigi.ir/
Approach to Diarrhea
Acute Diarrhea
Definitions

Diarrhea -working definition is:
 three or more loose or watery stools per day or
 definite decrease in consistency and increase in frequency
based upon an individual baseline
Acute — ≤14 days in duration
 Persistent diarrhea — more than 14 days in
duration
Chronic — more than 30 days in duration
Introduction
 One of the five leading causes of death worldwide
 Most cases of acute diarrhea are due to infections with
viruses and bacteria and are self-limited.
 Noninfectious etiologies become more common as the
course of the diarrhea persists and becomes chronic.
Noninfectious causes of diarrhea include drugs, food
allergies, primary gastrointestinal diseases such as
inflammatory bowel disease, and other disease states
such as thyrotoxicosis and the carcinoid syndrome.
Most cases of acute infectious gastroenteritis are probably viral,
In contrast, bacterial causes are responsible for most cases of severe diarrhea
DIAGNOSTIC APPROACH
careful history
 Duration of symptoms
 Frequency and characteristics of the stool.
 Complete past medical history (identify immunocompromised
host)
 Important to ask about recent antibiotic use
 A food history may also provide clues to a diagnosis:
 Within 6 hr
Staphylococcus aureus or Bacillus cereus
 Within 8 to 16 hr Clostridium perfringens
 More than 16 hr
viral or bacterial infection (
enterotoxigenic or enterohemorrhagic E. coli).
 Physical examination:
 fever, which suggests infection with :
 invasive bacteria (Salmonella, Shigella,
Campylobacter)
 Enteric viruses, or
 Cytotoxic organism such as Clostridium difficile or
Entamoeba histolytica

Evidence of extracellular volume depletion
(eg, decreased skin turgor, orthostatic hypotension
Bloody diarrhea
 E.coli O157:H7 (Most common)
 Less common bacterial causes :
 Shigella,
 Campylobacter,
 Salmonella species
Fecal leukocytes and occult blood
 Sensitivity and specificity ranging from 20 to 90
percent
 Because of these concerns about test performance, the
role of testing for fecal leukocytes has been
questioned .
 However, the presence of occult blood and fecal
leukocytes supports the diagnosis of a bacterial cause
of diarrhea
Uptoate:
we perform this examination in addition to obtaining
a bacterial culture in high risk patients.
Lactoferrin
 Lactoferrin is a marker for fecal leukocytes, but its
measurement is more precise
 sensitivity and specificity ranging from 90 to100
percent in distinguishing inflammatory diarrhea (eg,
bacterial colitis or inflammatory bowel disease) from
noninflammatory causes (eg, viral colitis, irritable
bowel syndrome)
When to obtain stool cultures
low rate of positive stool cultures in most
reports (1.5 to 5.6 percent)
most infectious causes of acute
diarrhea are self-limited
it is reasonable to continue symptomatic therapy for
several days before considering further evaluation
When to obtain stool cultures
we recommend obtaining stool cultures on initial presentation
in the following groups of patients:
 Immunocompromised patients, including those infected with
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HIV
Patients with comorbidities that increase the risk for
complications
Patients with more severe, inflammatory diarrhea (including
bloody diarrhea)
Patients with underlying inflammatory bowel disease in
whom the distinction between a flare and superimposed
infection is critical
Some employees, such as food handlers
When to obtain stool for ova and parasites
 Persistent diarrhea (associated with Giardia,
Cryptosporidium,and Entamoeba histolytica)
 Persistent diarrhea with exposure to infants in daycare
centers(associated with Giardia and Cryptosporidium)
 Diarrhea in a man who has sex with men (MSM) or a patient
with AIDS (associated with Giardia and Entamoeba histolytica in
the former, and a variety of parasites in the latter).
 A community waterborne outbreak (associated with Giardia and
Cryptosporidium)
 Bloody diarrhea with few or no fecal leukocytes (associated with
intestinal amebiasis)
Three specimens should be sent on consecutive days (or each specimen
separated by at least 24 hours)
TREATMENT
 Begins with general measures such as hydration and
alteration of diet.
 Antibiotic therapy is not required in most cases
since the illness is usually self-limited.
 Oral rehydration solutions:
 Oral rehydration solutions were developed
following the realization that, in many small bowel
diarrheal illnesses, intestinal glucose absorption via
sodium-glucose cotransport remains intact.
 The composition of the oral rehydration solution
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
(per liter of water) recommended by the World
Health Organization consists of:
3.5 g sodium chloride
2.9 g trisodium citrate or 2.5 g sodium bicarbonate
1.5 g potassium chloride
20 g glucose or 40 g sucrose
Enterohemorrhagic E. coli
 Antibiotics should be avoided in patients with
suspected or proven infection with enterohemorrhagic
E. coli (EHEC).
why
There is no evidence of benefit from antibiotic therapy
for EHEC infection
2.
there is concern about an increase in the risk of
hemolytic-uremic syndrome that might be mediated
by an increase in the production or release of Shiga
toxin when antibiotics are administered
 EHEC infection should be suspected in patients with
bloody diarrhea, abdominal pain and tenderness, but
little or no fever.
1.
Clostridium difficile
 Patients with acute diarrhea should be questioned
carefully about prior antibiotic therapy and other risk
factors for C. difficile infection.
 The appropriate therapy for this infection is:
Discontinuation of antibiotics, if possible,
2. Consideration of metronidazole or vancomycin if
the symptoms are more than mild or worsen or
persist
1.
When to treat
 Those with moderate to severe travelers' diarrhea as
characterized by more than four unformed stools daily, fever,
blood, pus, or mucus in the stool.
 Those with more than eight stools per day
 volume depletion
 symptoms for more than one week
 those in whom hospitalization is being considered
 Immunocompromised hosts
 Signs and symptoms of bacterial diarrhea such as fever,
bloody diarrhea (except for suspected EHEC or C. difficile
infection
 Presence of occult blood or fecal leukocytes in the stool.
Empiric antibiotic therapy
 empiric therapy:
 An oral fluoroquinolone ( ciprofloxacin 500 mg
twice daily, norfloxacin 400 mg twice daily, or
levofloxacin 500 mg once daily) for three to five
days in the absence of suspected EHEC or
fluoroquinolone-resistant campylobacter infection
 Azithromycin (500 mg PO once daily for three days)
or erythromycin (500 mg PO twice daily for five
days) are alternative agents if fluoroquinolone
resistance is suspected
Symptomatic therapy
 The antimotility agent loperamide (Imodium) may
be used in patients with acute diarrhea in whom
fever is absent or low grade and the stools are not
bloody
 The dose of loperamide is two tablets (4 mg)
initially, then 2 mg after each unformed stool, not to
exceed 16 mg/day for ≤2 days.
 Diphenoxylate has central opiate effects and may
cause cholinergic side effects
Symptomatic therapy
 patients should be cautioned that treatment with
these agents may mask the amount of fluid lost,
since fluid may pool in the intestine.
 Thus, fluids should be used aggressively when
antimotility agents are employed.
 Another potential problem is that both drugs may
facilitate the development of the hemolytic-uremic
syndrome (HUS) in patients infected with EHEC
Symptomatic therapy
 Bismuth subsalicylate (Pepto-Bismol) has also been
used for symptomatic treatment of acute diarrhea.
 compared with placebo, bismuth subsalicylate is
significantly better but compared with loperamide,
loperamide is better
 A role for bismuth subsalicylate may be in patients
with significant fever and dysentery, conditions in
which loperamide should be avoided.
 Two tablets every 30 minutes for eight doses
Probiotics
 Probiotics, including bacteria that assist in
recolonizing the intestine with non-pathogenic
flora, can also be used as alternative therapy.
 Probiotics is useful in treating traveler's diarrhea
 diarrhea and acute non-specific diarrhea in
children.
Dietary recommendations
 The benefit of specific dietary recommendations other than
oral hydration has not been well-established in controlled
trials.
 Adequate nutrition during an episode of acute diarrhea is
important to facilitate enterocyte renewal
 Boiled starches and cereals (eg, potatoes, noodles, rice,
wheat, and oat) with salt are indicated in patients with
watery diarrhea;
 crackers, bananas, soup, and boiled vegetables may also be
consumed
 Foods with high fat content should also be avoided
 In addition, secondary lactose malabsorption is common
following infectious enteritis and may last for several weeks
to months. Thus, temporary avoidance of lactose-containing
foods may be reasonable
Chronic Diarrhea
EPIDEMIOLOGY
 Chronic diarrhea affects approximately 5 percent
of the population
 More than $350,000,000 annually from work-loss
alone
ETIOLOGY
 The principal causes of diarrhea depend upon the
socioeconomic status of the population.
 In developing countries, chronic diarrhea is frequently
caused by chronic bacterial, mycobacterial and parasitic
infections, although functional disorders, malabsorption,
and inflammatory bowel disease are also common.
 In developed countries, common causes are irritable
bowel syndrome (IBS), inflammatory bowel disease,
malabsorption syndromes (such as lactose intolerance
and celiac disease), and chronic infections (particularly in
patients who are immunocompromised).
EVALUATION
 Optimal strategies for the evaluation of patients with
chronic diarrhea have not been established
Recommendations have been derived mostly from
expert opinion and from experience
 The selection of specific tests, timing of referral, and
the extent to which testing should be performed
depend upon an appraisal of the likelihood of a
specific diagnosis, the availability of treatment, the
severity of symptoms, patient preference, and
comorbidities.
History
1) A clear understanding of what led the patient to
2)
3)
4)
5)
6)
complain of diarrhea(eg, consistency or frequency of
stools, the presence of urgency or fecal soiling)
Stool characteristics (eg, greasy stools that float and
are malodorous may suggest fat malabsorption while
the presence of visible blood may suggest
inflammatory bowel disease)
Duration of symptoms, nature of onset (sudden or
gradual)
Travel history
Risk factors for HIV infection
Weight loss
History
7) Whether there is fecal incontinence (which may be
confused with diarrhea)
8) Occurrence of diarrhea during fasting or at night
(suggesting a secretory diarrhea)
9) Family history of IBD
10) The volume of the diarrhea (eg, voluminous watery
diarrhea is more likely to be due to a disorder in the
small bowel while small-volume frequent diarrhea is
more likely to be due to disorders of the colon)
11) The presence of systemic symptoms, which may
indicate inflammatory bowel disease (such as
fevers, joint pains, mouth ulcers, eye redness)
History
12) All medications (including over-the-counter drugs
and supplements)
13) A relevant dietary (including possible use of
sorbitol-containing products and use of alcohol)
14) Association of symptoms with specific food
ingestion (such as dairy products or potential food
allergens)
15) A sexual history (anal intercourse is a risk factor for
infectious proctitis and promiscuous sexual activity
is a risk factor associated with HIV infection) ·
16) A history of recurrent bacterial infections (eg,
sinusitis, pneumonia),which may indicate a primary
immunoglobulin deficiency.
Physical examination

The physical examination rarely provides a specific
diagnosis. However, a number of findings can provide
clues These include:
1) findings suggestive of IBD (eg, mouth ulcers, a skin rash,
episcleritis, an anal fissure or fistula,
2) the presence of visible or occult blood on digital
examination,
3) abdominal masses or abdominal pain
4) evidence of malabsorption (such as wasting,
physical signs of anemia, scars indicating prior
abdominal surgery)
5) Lymphadenopathy (possibly suggesting HIV
infection),
6) Abnormal anal sphincter pressure or reflexes
(possibly suggesting fecal incontinence)
7) Palpation of the thyroid and examination for
exophthalmos and lid retraction may provide
support for a diagnosis of hyperthyroidism.
laboratory evaluation
 A large number of tests are available for
diagnosing specific causes of diarrhea
 There is no firm rule as to what testing should be
done.
 The history and physical examination may point
toward a specific diagnosis for which testing may
be indicated
laboratory evaluation
 The minimum laboratory evaluation in most
patients should include a complete blood count
and differential, erythrocyte sedimentation rate,
thyroid function tests, serum electrolytes, total
protein and albumin, and stool occult blood
 most patients require some form of endoscopic
evaluation and mucosal biopsy (either
sigmoidoscopy, colonoscopy, or sometimes upper
endoscopy), depending upon the clinical setting
 Another useful way to guide specific testing is to
attempt to categorize diarrhea as:
watery diarrhea(secretory or osmotic)
fatty diarrhea
inflammatory diarrhea
Secretory diarrhea
 continues despite fasting
 is associated with stool volumes >1 liter/day
 occurs day and night (in contrast to osmotic
diarrhea)
 Although usually unnecessary, the distinction
between an osmotic and a secretory diarrhea can
also be established by measuring stool
electrolytes and calculating an osmotic gap.
osmotic gap
 (290 - 2 ({Na+} + {K+})
 An osmotic gap of >125 mOsm/kg suggests an
osmotic diarrhea
 while a gap of <50 mOsm/kg suggests a
secretory diarrhea
 Further testing in patients with secretory diarrhea
may include:
1) stool cultures to exclude chronic infection,
2) imaging of the small and large bowel
3) selective testing for secretagogues, such as
gastrin or vasoactive intestinal polypeptide
osmotic diarrhea
 Further testing in patients with osmotic diarrhea
may be unnecessary if the osmotic agent can be
identified based upon the history.
 An example is inadvertent ingestion of sorbitol
(such as in sugarless candies) or lactose in
patients who have lactose intolerance.
 Temporary avoidance of lactose-containing foods
can help establish the diagnosis of lactose
intolerance in patients who were unaware of the
diagnosis.
 Testing the stool for laxatives may occasionally
be required if laxative abuse is suspected.
 Laxative abuse can be suggested by the
presence of melanosis coli on sigmoidoscopy or
colonoscopy.
Inflammatory diarrhea
1)
2)
3)
4)
5)
6)
Inflammatory diarrhea should be suspected in
patients with:
clinical features suggesting inflammatory bowel
disease,
clinical features suggesting C. difficile infection
those at risk for opportunistic infections such as
tuberculosis
those with a travel history.
Serum markers of acute inflammation (such as the
sedimentation rate and C-reactive protein levels
fecal leukocytes and Fecal calprotectin
Inflammatory diarrhea
 Diagnosis can usually be established by:
 sigmoidoscopy or colonoscopy or
 by analysis of stool specimens (ie, culture or
testing for C. difficile toxin).
Fatty diarrhea
 Fatty diarrhea (steatorrhea) should be suspected in
patients who report greasy, malodorous stools and
those who are at risk for fat malabsorption, such as
patients with chronic pancreatitis.
 A variety of tests can be used to confirm the
diagnosis.
 Currently, the gold standard for diagnosis of
steatorrhea is quantitative estimation of stool fat.
empiric therapy
 empiric therapy may be warranted in certain situations:
 · When comorbidities limit diagnostic evaluation.
 · When a diagnosis is strongly suspected.
 Examples include a daycare worker who develops
diarrhea after a known outbreak of Giardiasis
 a patient who develops diarrhea following limited (<100
cm) ileal resection in whom bile acid malabsorption is
likely,
 a patient with known recurrent bacterial overgrowth,
 and an otherwise healthy patient with suspected lactose
intolerance
DEFINITION
 Watery Diarrhea: 3 or more liquid or watery stools in 24 h
 Dysentery: Presence of blood and/or mucus in stools
 Persistent Diarrhea: Diarrhea lasting for 14 days or more
TYPES OF DIARRHEA
Diarrhea
Watery diarrhea
Dysentery
Persistent diarrhea
Rota virus diarrhea
E. coli diarrhea
Cholera
Shigellosis
Amebiasis
Causes are mostly unknown
COMMON CAUSES OF DIARRHEABACTERIA
 Vibrio cholera
 Shigella
 Escherichia coli
 Salmonella
 Campylobacter jejuni
 Yersinia enterocolitica
 Staphylococcus
 Vibrio parahemolyticus
 Clostridium difficile
COMMON CAUSES OF DIARRHEAVIRUS
• Rotavirus
• Adenoviruses
• Caliciviruses
• Astroviruses
• Norwalk agents and Norwalk-like viruses
COMMON CAUSES OF DIARRHEAPARASITE
• Entameba histolytica
• Giardia lamblia
• Cryptosporidium
• Isospora
COMMON CAUSES OF DIARRHEAOTHERS
• Metabolic disease
Hyperthyroidism
Diabetes mellitus
Pancreatic insufficiency
• Food allergy
Lactose intolerance
• Antibiotics
• Irritable bowel syndrome
TRANSMISSION
 Most of the diarrheal agents are transmitted by the fecal-oral
route
 Some viruses (such as rotavirus) can be transmitted through
air
 Nosocommial transmission is possible
 Shigella (the bacteria causing dysentery) is mainly transmitted
person-to-person
SEASONALITY
Disease
Common season
Cholera
Winter
Rotavirus diarrhea Winter
Shigellosis
Dry summer
PERSON-AT-RISK
 Cholera: 2 years and above, uncommon in very young infants
 Shigellosis: more common in young children aged below 5
years
 Rotavirus diarrhea: more common in young infants and
children aged 1-2 years
 E. coli diarrhea: can occur at any age
 Amebiasis: more common among adults
TYPES OF VIBRIO CHOLERA
 Two major biotypes of Vibrio cholera that cause diarrhea are:
Classical
ElTor
 Two common serotypes of Vibrio cholera that cause diarrhea
are:
Inaba
Ogawa
Vibrio cholerae O139
 Vibrio cholerae in O-group 139 was first isolated in 1992
and by 1993 had been found throughout the Indian
subcontinent. This epidemic expansion probably resulted
from a single source after a lateral gene transfer (LGT)
event that changed the serotype of an epidemic V. cholerae
O1 El Tor strain to O139.
 More information:
http://www.cdc.gov/ncidod/EID/vol9no7/020760.htm
Vibrio vulnificus
 The organism Vibrio vulnificus causes wound infections, gastroenteritis or a
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serious syndrome known as "primary septicema."
V. vulnificus infections are either transmitted to humans through open wounds in
contact with seawater or through consumption of certain improperly cooked or
raw shellfish.
This bacterium has been isolated from water, sediment, plankton and shellfish
(oysters, clams and crabs) located in the Gulf of Mexico, the Atlantic Coast as
far north as Cape Cod and the entire U.S. West Coast.
Cases of illness have also been associated with brackish lakes in New Mexico
and Oklahoma.
For more information: http://hgic.clemson.edu/factsheets/HGIC3663.htm
TYPES OF SHIGELLA
 The major serotypes of Shigella that cause diarrhea are:
Dysenteriae type 1 or Shigella shiga
Shigella flexneri
Shigella sonnei
Shigella boydii
TYPES OF E. COLI
 Six major types of Escherichia coli cause diarrhea:
 Enterotoxigenic E. coli (ETEC)
 Enteroinvasive E. coli (EIEC)
 Enteropathogenic E. coli (EPEC)
 Enterohemorrhagic E. coli (E. coli O157:H7)
 Enteroaggregative E. coli (EAggEC)
 Diffuse adherent E. coli (DAEC)
CLINICAL FEATURE: CHOLERA
 Rice-watery stool
 Marked dehydration
 Projectile vomiting
 No fever or abdominal pain
 Muscle cramps
 Hypovolemic shock
 Scanty urine
CLINICAL FEATURE:
E. COLI DIARRHEA
 Watery stools
 Vomiting is common
 Dehydration moderate to severe
 Fever– often of moderate grade
 Mild abdominal pain
CLINICAL FEATURE:
ROTAVIRUS DIARRHEA
 Insidious onset
 Prodromal symptoms, including fever, cough, and vomiting
precede diarrhea
 Stools are watery or semi-liquid; the color is greenish or
yellowish– typically looks like yoghurt mixed in water
 Mild to moderate dehydration
 Fever– moderate grade
CLINICAL FEATURE:
SHIGELLOSIS
 Frequent passage of scanty amount of stools, mostly mixed
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with blood and mucus
Moderate to high grade fever
Severe abdominal cramps
Tenesmus– pain around anus during defecation
Usually no dehydration
CLINICAL FEATURE:
AMEBIASIS
 Offensive and bulky stools containing mostly mucus and
sometimes blood
 Lower abdominal cramp
 Mild grade fever
 No dehydration
LABORATORY DIAGNOSIS
 Stool microscopy
 Dark field microscopy of stool for cholera
 Stool cultures
 ELISA for rotavirus
 Immunoassays, bioassays or DNA probe tests to identify E.
coli strains
ASSESSMENT OF DEHYDRATION
Dehydration
Mild
Moderate Severe
Appearance irritable, irritable, lethargy,
thirsty
very
coma, or
thirsty
unconscious
Anterior
normal
depressed markedly
Fontanelle
depressed
Eyes
normal
sunken
sunken
ASSESSMENT OF DEHYDRATION
(contd.)
Tongue
Mild
normal
Skin
normal
Breathing normal
Dehydration
Moderate Severe
dry
very dry,
furred
slow
very slow
retraction retraction
rapid
very rapid
ASSESSMENT OF DEHYDRATION
(contd.)
Pulse
Mild
normal
Urine
normal
Dehydration
Moderate Severe
rapid and feeble or
low
imperceptible
volume
dark
scanty
Weight
loss
< 5%
6 - 9%
10% or more
TREATMENT
 Rehydration– replace the loss of fluid and electrolytes
 Antibiotics– according to the type of pathogens
 Start food as soon as possible
COMPOSITION OF ORS
Ingredient
Sodium chloride
Amount (g/liter)
3.5
Trisodium citrate or
Sodium bicarbonate
2.9 or
2.5
Potassium chloride
1.5
Glucose
20.0
AMOUNT OF SALT LOSS DURING
DIARRHEA
Diarrhea
Cholera
(child)
Salt (mmol/L)
Na K Cl HCO3
88 30 86 32
Cholera
(adult)
135 15 100 45
E. coli
Rota
virus
53
37
37 24
38 22
18
6
ANTIMICROBIAL AGENTS
Type of diarrhea
Cholera
Antimicrobial agent
Tetracycline,
Doxycycline,
Ciprofloxacine
Shigellosis
Pivmecillinam
(Selexid), Nalidixic
acid, Ciprofloxacin,
Ceftriaxone
Metronidazole
Amebiasis
COMPLICATIONS:
WATERY DIARRHEA
 Dehydration
 Electrolyte imbalances
 Tetany
 Convulsions
 Hypoglycemia
 Renal failure
COMPLICATIONS:
DYSENTERY
 Electrolyte imbalances
 Convulsions
 Hemolytic uremic syndrome (HUS)
 Leukemoid reaction
 Toxic megacolon
 Protein losing enteropathy
 Arthritis
 Perforation
VACCINES
 An oral cholera vaccine is available, which gives immunity to
50-60% of those who take the vaccine, and this immunity
lasts only a few months.
 No vaccines are available against shigellosis
 A vaccine against rotavirus diarrhea has been withdrawn
recently from the market.
PREVENTION
 Safe drinking water and food
“Boil it, cook it, peel it, or forget it. "
 Hand washing
 Proper sanitation