GASTROENTERITIS
Dr. Bikha Ram Devrajani
MBBS(SINDH),FCPS(PAK),FACP(USA),FRCP(LONDON)
Professor Medicine
Liaquat University of Medical & Health Sciences
Jamshoro
Gastroenteritis

Gastroenteritis is a nonspecific term for a
variety of pathologic states of the
gastrointestinal tract.

The primary manifestation is diarrhea, but
it may be accompanied by nausea,
vomiting, and abdominal pain.

A universal definition of diarrhea does not
exist, although patients seem to have no
difficulty defining their own situation.
Gastroenteritis

Although most definitions center around
the frequency, consistency, and water
content of stools, the author prefers the
definition that diarrheal stools take the
shape of their container.
Gastroenteritis

Severity of illness may vary from mild and
inconvenient to severe and life threatening.

Appropriate management requires
extensive history and assessment and
appropriate general supportive and, often,
etiology-specific treatment.

Diarrhea associated with nausea and
vomiting is referred to as
gastroenteritis.
Diarrhea is……..

A symptom characterized by an
abnormal increase in stool
frequency or liquidity

Acute diarrhea is usually self
limiting and lasts 48-72 hours,
sometimes up to 7 days

Chronic diarrhea lasts more than 4
weeks, should seek medical care
Global Problem

4.6 million children less
than 5 years of age die
of diarrheal diseases.

Diarrhea accounts for
19% of all deaths among
children ages 0-4.

Eighty-five percent of
diarrheal deaths occur in
the first year of life.
World Health Organization. 1997. WHO Fact Sheet: Reducing Mortality from Major Childhood Killer Diseases. Fact Sheet Number
180. http://www.who.int/chd/pub/imci/fs_180.html
Centers for Disease Control and Prevention. 1992. Diarrhea: The Management of Acute Diarrhea in Children: Oral Rehydratioin,
Maintenance, and Nutritional Therapy. http://www.rehydrate.org/html
Graph. http://www.who.int/chd/images/deaths.gif
OUTBREAKS

July 1998: E coli 0157:H7 infection
outbreak from contaminated water supply
in Wyoming, more than 60 infected

July 1995: 77 cases of cryptosporidiosis at
a day camp in Florida, most likely
secondary to water hose contamination

August-September 1999: E coli 0157:H7
infections secondary to contaminated well
water in Washington County Fair (New
York)
OUTBREAKS

Three to five billion cases of acute
diarrhea occur yearly, and it is the leading
cause of death in many underdeveloped
countries.

Approximately 30-50% of visitors to
developing countries will develop, and
perhaps return with, diarrhea.
Age

Gastroenteritis may occur at any age.

Morbidity and mortality are much higher in
the very young and the very old.
Transmission
• Diarrheal agents are mostly spread via the
fecal-oral route.
– physical contact with infected feces
– eating or drinking contaminated food or water
– person to person relay
World Health Organization. 1998. The Epidemiology and Etiology of Diarrhea. http://www.who.int/chd/pub/cdd/meded/1med.html
Socioeconomic factors
•
•
•
•
•
Poverty
Overcrowding
Poor sanitation
Contamination of
water
Inadequate food
hygiene
UNICEF. 1998. The State of the World’s Children, 1998. Oxford and New York: Oxford University Press.
Diarrheal illnesses also may be
classified
• Osmotic, due to an increase in the osmotic
load presented to the intestinal lumen,
either through excessive intake or
diminished absorption
• Inflammatory (or mucosal), when the
mucosal lining of the intestine is inflamed.
• Secretory, when increased secretory activity
occurs
• Motile, caused by intestinal motility
disorders
Etiological Agents
• Bacterial, Viral, and
• Protozoans
Parasitic Agents
• Giardia
• Rotavirus
Rotavirus
• Enterotoxigenic E. Coli
• Shigellae
• Salmonellae
• Vibrio Cholerae
• Campylobacter jejuni
• Cryptosporidium
Giardia
E.Coli
• Entamoeba
World Health Organization. 1997.
http://www.who.int/chd/pub/imci/fs_180.html
Etiology of diarrhea
• Diarrhea is a symptom of an underlying
•
•
•
•
•
•
pathology or infection
Viral gastroenteritis
Bacterial gastroenteritis
Protozoal diarrhea
Antibiotic associated diarrhea
AIDS associated diarrhea
Food-induced diarrhea
Etiology of diarrhea
• Viral (50-70%)
– The Norwalk virus is the leading cause of viral gastroenteritis in the
United States. Norwalk virus belongs to the species of Noroviruses
(formerly known as Norwalk-like viruses). Noroviruses, along with
the Sapoviruses (formerly known as Sapporo-like viruses) are
members of the Caliciviridae family of viruses.
– Caliciviruses: Various caliciviruses, other than Norwalk, are likely
responsible for many out breaks of previously unidentified viral
gastroenteritis.
– Rotavirus: A leading cause of gastroenteritis in
children, but can also be found in adults. May
cause severe dehydration.
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–
–
–
–
–
Adenovirus
Parvovirus
Astrovirus
Coronavirus
Pestivirus
Torovirus
Etiology of diarrhea
• Bacterial (15-20%)
– Shigella
– Salmonella
– C jejuni
– Yersinia enterocolitica
– E coli - Enterohemorrhagic 0157:H7,
enterotoxigenic, enteroadherent, enteroinvasive
– V cholera
–
–
–
–
–
–
–
–
–
Aeromonas
B cereus
C difficile
Clostridium perfringens
Listeria
Mycobacterium avium-intracellulare (MAI), immunocompromised
Providencia
Vibrio parahaemolyticus
Vibrio vulnificus
Etiology of diarrhea
• Parasitic (10-15%)
– Giardia
– Amebiasis
– Cryptosporidium
– Cyclospora
• Food-borne toxigenic diarrhea
– Preformed toxin - S aureus, B cereus
– Postcolonization - V cholera, C perfringens,
enterotoxigenic E coli, Aeromonas
Etiology of diarrhea
• Shellfish poisoning and poisoning from other
marine animals
– Paralytic shellfish poisoning (PSP) - Saxitoxin
– Neurologic shellfish poisoning (NSP) - Brevotoxin
– Diarrheal shellfish poisoning (DSP) - Okadaic acid
– Amnesic shellfish poisoning - Domoic acid
– Ciguatera (ciguatoxins)
– Scombroid (conversion of histidine to histamine)
Etiology of diarrhea
• Drug-associated diarrhea
–
–
–
–
–
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Antibiotics due to alteration of normal flora
Laxatives, including magnesium-containing antacids
Colchicine
Quinidine
Cholinergics
Sorbitol
• Pseudomembranous colitis
– Overgrowth of C difficile
– Positive C difficile assay
Etiology of diarrhea
• Other causes
–
–
–
–
–
Unknown agents, especially in developing countries
Ischemic colitis
Ulcerative colitis
Crohn disease
Carcinoid tumor or vasoactive intestinal peptide tumor
(VIPoma)
– AIDS
– Dumping or short bowel syndrome
– Radiation or chemotherapy
Viral gastroenteritis
• 80-85% of episodes of acute
diarrhea are caused by viruses
• Virus transmitted by contaminated
food or water
• Clinical features include 12-48hr
incubation period followed by
vomiting, watery diarrhea and low
grade fever
• Illness lasts 5-8 days, treatment is
fluid and electrolyte therapy
Bacterial gastroenteritis
• Common pathogens are Campylobacter,
Salmonella, Shigella, E.coli, Staphylococcus,
Clostridium
• If attack is in small intestine patients usually
•
experience abrupt onset of large volume,
watery stools, upper abdominal pain, nausea,
vomiting, cramps, and low grade fever
If attack is in large intestine, patients may
experience dysentery like syndrome including
bloody or mucousy diarrhea
Traveler’s diarrhea
• A form of bacterial gastroenteritis
• Usually occurs when people travel to
warmer climates with poor sanitation
• Most commonly caused by E.coli
• Characterized by sudden onset of loose
stools, nausea, occasional vomiting,
cramps, bloating, malaise and low grade
fever
• Usually subsides over 3-4 days
Protozoal diarrhea
• Giardia lamblia and entamoeba histolytica
are protozoa associated with diarrhea
• Usually acquired traveling to mountainous
or recreational water areas, drinking stream
or pond water
• No nonprescription therapy for protozoal
diarrhea, metronidazole is treatment of
choice
Antibiotic associated diarrhea
• Frequency of diarrhea is largely dependent on
•
•
the extent to which the drug disrupts the
normal intestinal flora
Abx that have broad spectrum activity against
aerobes and anaerobes can produce diarrhea
AAD may be caused by an overgrowth of abx
resistant bacteria, fungi, or toxin producing
C.difficile
• Diarrhea caused by C.difficile is usually watery
•
and greenish-mucoid
There are no nonprescription treatments for
eradicating C.difficile
AIDS Associated Diarrhea
• Patients with AIDS or HIV are known to
be susceptible to intestinal infections that
produce diarrhea
• These patients should not self-manage
their diarrhea, they should see their
physician
Food-Induced Diarrhea
• Food intolerance can provoke diarrhea
• The enzyme lactase hydrolyzes
disaccharides into monosaccharides
• When you lack the lactase enzyme,
disaccharides can not be hydolyzed to
monosaccharides
• Disaccharides pool in lumen causing an
osmotic imbalance which draws fluid
into the lumen and causes diarrhea
Signs of Dehydration
• Common: dizziness, thirst, confusion, lethargy,
•
•
•
•
•
fatigue
Serious: low BP, fever, vomiting, abdominal
cramps, nausea, muscle aches, mucously stools,
weight-loss
Mild dehydration: 3-5% weight-loss
Severe dehydration: 10% weight-loss (can be very
serious in infants, may lead to cardiovascular
collapse and renal failure
Mild/moderate diarrhea are self-treatable
Severe diarrhea: non self-treatable
Laboratory Investigations





Stool DR, ova & cyst, and C/S.
CBC.
Serum electrolytes.
Blood urea.
Other investigations depend upon the
causative agent.
Treatment Options
Treatment Outcomes
1. Assess and Correct electrolyte
and fluid loss
2. Manage diet or disease
3. Provide relief
4. Identify cause
Oral Rehydration Therapy
Fluid and Electrolyte Replacement
Not more than 75-90 mEq/L of Na
for rehydration
 Not more than 40-60 mEq of Na
for maintenance
 Carb to Na ratio should be 2:1
 Important in children and infants
 All patients should rehydrate and
maintain during diarrheal episode

Loperamide
Good for treatment of traveler’s
diarrhea and IBD
 Works by slowing intestinal motility
 Use 4mg initially, then 2mg after
each loose stool but do not exceed
16mg/day (8 tablets)
 Do not use in children <6 years old
use electrolyte tx instead

Absorbents

Include attapulgite, kaolin,
pectin

Do not recommend because of
decreased absorption of other
drugs
Things to Remember
Always remember to rehydrate
 Special populations (elderly, <3
years old, pregnant) require
medical referral
 Healthy patients usually improve
within 24 to 48 hours
 If condition remains or worsens
after 48 hours - refer to MD

Complications of Diarrhea

Acute diarrhea may cause severe
dehydration and electrolyte imbalance

Infants, young children, and the elderly
are most at risk for dehydration

Children less than 2 yrs of age often
have complications that require
hospitalization
First steps for
managing an
outbreak of acute
diarrhoea
THIS PRESENTATION AIMS AT GUIDING
YOU THROUGH THE VERY FIRST DAYS OF
AN OUTBREAK
WORLD HEALTH ORGANIZATION
Is this the beginning of an
outbreak?
WORLD HEALTH ORGANIZATION
You might be facing an outbreak very soon if
 You have seen an unusual number of acute
diarrhoeal cases this week and the patients have
the following points in common:
– they have similar clinical symptoms (watery or bloody
diarrhoea)
– they are living in the same area or location
– they have eaten the same food (at a burial ceremony for
example)
– they are sharing the same water source
– there is an outbreak in the neighbouring community
WORLD HEALTH ORGANIZATION
or
 You have seen an adult suffering from
acute watery diarrhoea with severe
dehydration and vomiting

If you have some statistical
information from previous years or
weeks verify if the actual increase of
cases is unusual over the same
period of time.
WHAT DO I HAVE TO DO WHEN I
SUSPECT AN OUTBREAK?
1. Inform and ask for help
2. Protect the community
3. Treat the patients
diarrhea
MESSAGE TO THE COMMUNITY
MESSAGE TO THE COMMUNITY
MESSAGE TO THE COMMUNITY
MESSAGE TO THE COMMUNITY
PROTECT YOURSELF FROM
CONTAMINATION

Wash your hands with soap before
and after taking care of the patient

Cut your nails
3. TREAT THE PATIENTS

80% of the cases can be treated with Oral
Rehydration Salt (ORS)
Mortality/Morbidity
Estimates for mortality and morbidity vary
widely. In the United States, 210,000
pediatric hospitalizations occur yearly with
as many as 10,000 deaths.

Internationally, mortality rate is 5-10
million deaths each year.
Thank
you