Download tests that may be useful in evaluation of patients with acute diarrhea

Diarrhea
is loosely defined as passage
of abnormally liquid or unformed
Stool at an increased frequency.
For adults on a typically western
Diet, stool weight exceeding 200g/d
Can generally be considered diarrheal.
Pathophysiologic classification of diarrhea
 Secretory diarrhea
 Osmotic
diarrhea
 Inflammatory ( exudative )
diarrhea
 Motility ( dismotile ) diarrhea
 Anatomic ( decreased absorptive surface)
Secretory diarrhea
 Increased
secretion and / or
decreased absorption of electrolytes.
 Large volume watrey stool,no blood,
no FSG, no pus, no response to
fasting.
 Small intestine type diarrhea.
Some causes of
Secretory diarrhea
 Cholera
,Ecoli, and Salmonella toxins.
 Serotonine,VIP,Calcitonine,Bile acids.
 Castrol oil, Biscodyl, Senna,
 Villus atrophy (Celiac sprue , Int. lymphoma).
 Collagen vascular dis.) ( SLE , MCTD
OSMOTIC DIARRHEA
 Non
absorbable,osmoticlly active
molecules in gut lumen.
 Watrey stool, no blood, no pus in the
stool.
 Improves with fasting.
 May have high FSG.
FSG = 280 – (fecal Na + fecal K ) * 2
Some causes of osmotic diarrhea
 Disacaridase
deficiencies.
 Lactulose, Manitol, Sorbitol, Mg ++
 Sulfate, phosphate (Laxatives).
 Sodium citrate ingestion.
 Steatorrhea, generalized
malabsoption.
 Rotavius induced diarrhea.
EXUDATIVE DIARRHEA
Destruction
of intestinal
mucosa.
Small frequent bloody stools
with pus, and tenesmus.
Fever
Large intestine type diarrhea.
Some causes of exudative diarrhea
Entero-invasive
E.coli
Shigella
E.
histolitica
Ulcerative colitis
Ischemic colitis
Acute
if < 2 weeks
Persistent if 2 to 4 weeks
Chronic if > 4 weeks
Epidemiology of
Acute Diarrhea
Worldwide,
>1000,000,000
people/year
5 -8 million deaths / year in
developing countries.
3000/year mortality in US.
High risk groups for diarrhea

Travelers.
40 % of tourists develop diarrhea
Most commonly duo to ETEColi

Consumers of certain foods.
Picnic, restaurant, undercooked
hamberger, seafoods(raw)

Immunodeficient persons
 Daycare participants and their
family members.
 Institutionalized persons.
Gastrointestinal Viruses
Virus type
Major risk group
Rotavirus
Seasonality Dx test
Children< 3 y Winter
Rx
ELISA ORS
(groupA)
Adenovirus
children< 3y
year-round ELISA ORS
(types 40,41)
Calicivirus
Astrovirus
Norwalk like
viruses
young
children
young
children
children ,
adults
unknown
EM(?)
ORS
winter
EM(?)
ORS
winter
EM (?) ORS
Factors that influence virulance of
entric pathogens
 Inoculum
size (Shigella,EPEC,giardia 10-100)
 Adherence
 Toxin production (enterotoxin, cytotoxin, neurotoxin)
 Invasion
 Normal flora of the host
 Gastric acid
 Intestinal motility
 Immunity
Major Causes of Acute Diarrhea

INFECTIONS (Including Travelers Diarrhea)
Bacterial : Campylobactre Species, C.difficile, E.coli, Salmonella eneritides
,
Shigella Species
Parasitic/protozoal : E. histolytica, Giardia lambilia,Cryptosporidium ,Cyclospoa
Viral : Adenovirus , Norwalk virus , Rotavirus ,AIDS, Others
Fungal

FOOD POISONING :

MEDICATIONS
RECENT INGESTION OF LARGE AMOUNT OF
POORLY ABSORBABLE SUGARS
INTESTINAL ISCHEMIA
FECAL IMPACTION
PELVIC INFLAMMATION
GRAFT VS HOST DISEASE





B.Cereus , C . Perfringens , Salmonella species ,
S .aureus, Vibrio species, Shigella species , Camppylobacter.jejuni, E.coli
MAJOR CAUSES OF CHRONIC DIARRHEA

IBS
 IBD
 Ischemic bowel disease
 Chronic bacterial / mycobacterial infection
 Parasitic & fungal infections
 Radiation enteritis
 Malabsorption Syndromes
 Medications, Alcohol
 Colon cancer , Villous Adenoma ,intestinal Lymphoma
 Diverticulitis
 Previous Surgery ( gastrectomy, vagatomy, intestinal resection )
 Endocrine causes
 Fecal impaction
 Heavy metal poisoning
 Epidemic idiopathic chronic diarrhea
1.
2.
3.
4.
5.
6.
7.
Indications for evaluation a patient
with acute diarrhea
Profuse diarrhea with dehydration.
Grossly bloody diarrhea.
Fever > or = 38.5 C
New community outbreaks.
Associated sever abdominal pain in
patients older than 50 years.
Elderly (> or = 70).
Immunocompromised patients.
TESTS THAT MAY BE USEFUL IN EVALUATION OF
PATIENTS WITH ACUTE DIARRHEA

Stool Exam for:
WBCs , Ova of parasites , Culture for
bacteria & virus , Clostridium difficile toxin ,
Giardia , Entameba , Viral antigens ( Rotavirus )

Blood test for:
CBC , Na , K , BUN , Creatinine ,
Culture

Flexible Sigmoidoscopy
 Abdominal Radiograph
Acute diarrhea
Likely
infectious
Mild
Likely
noninfecutios
Hx & P.Ex
Moderate
Severe
Activities altered
(Incapacitated)
Evaluate
& Rx
Institue fluid & electrolyte replacement
Observe
Fever >38 .bloody stool, fecal WBCs
Immunocompromised or elderly host
Resolves
No
Yes
Stool microbiology study
No
Pathogen
found
Specific Rx
Yes
Antidiarrheal agents
Persist
Empiric Rx +further evaluation
Empiric treatment in acute diarrhea
 Moderately
to severly ill patients
with febrile desentry.
Give Ciprofluxacin 500 mg bid for 3-5
days.
 Suspected Giardiasis Rx with
Metronidazole 250 mg qid for 7
days.
Indications of antibiotic coverage
wether or not a causative organism is
discovered in acute diarrhea
1.
2.
3.
Immunecompromised patient.
Mechanical heart valves or
recent vascular graft.
Elderly.
Antibiotic prophylaxis is indicated for
travelers (to high risk countries), with
Gastric achlorhydria
2. IBD
3. Immunocompromise
1.
Give Co-trimoxazole
Ciprofluxacine
or
Thank you
The end