This document defines diarrhea and classifies it as acute, persistent, or chronic based on duration. It then discusses the various causes of acute diarrhea including infectious agents like bacteria, viruses, protozoa, and helminths. Other potential causes mentioned are medications, toxins, diet, ischemia, and psychological stress. The document goes on to discuss specific infectious causes like cholera in more detail, describing the organism, transmission, pathogenesis, signs and symptoms, diagnosis, and treatment options. Prevention strategies discussed include education, sanitation improvements, and vaccination.

1. Dr. Nabila Hassan
MD. Tropical Medicine

2. Definition:
It means an increase of stool liquidity , quantity
(N: 200g/d) or frequency (N: 3-4 motions/d).
classsification
 acute if <2 weeks,
 persistent if 2–4 weeks,
 chronic if >4 weeks

3. Acute Diarrhea:
 >90% caused by infectious agents
 Remaining 10% medications, toxic, ischemia
1- Infection:
Bacterial : Salmonella , Shigella , E.coli , Campylobacter, Cholera,
(Salmonella,Staph, Clostridium)
Viral : Rota virus , Norwalk virus, Adenovirus, enterovirus.
Protozoa: E.histolytica , Malaria , Giaradia, Blantadium coli
Helminthes: Trichinella spiralis, strongyloids stercoralis.

4. 2- Iatrogenic:
* Laxatives * Antibiotic * Chemotherapy * Parasympathetic *
Mg containing antacid. * allopurinol
3- Toxins: *-Lead - arscenic- Mercury- Bacterial toxins
4- Diet:* Unripe fruit * Alcohol * Mushroom. * food allergy
5- Nervous: psychological stress
6- Ischemic colitis

5. 1- malabsorption syndrome. ( enumerate its causes )
2- Diseases of the colon : (ABCD)
Ameabic ---- AIDS--------Bilharizal--------Cancer colon& IBD-----
Diverticulosis.
3- Endocrinal causes :
• Thyrotoxicosis.
• Diabetic neuropathy.
• Addison’s disease.
• Zollinger Ellison syndrome.
• Carcinoid syndrome
• Pancreatic cholera (verner Morrison syndrome)

6. 4- Drugs:
 Laxative
 Anti- acids
- inflammatory
- arrhythmia
- biotics
- neoplastic

7. 1. Osmotic diarrhea:
Presence of non absorbed , hypertonic substances in
intestinal lumen maintain fluid & prevent absorption (e.g.
lactulose, sorbitol, magnesium ).
2. Secretory diarrhea (watery diarrhea) :
increase secretion of water & electrolytes into the
lumen.e.g. cholera , E.coli , _ VIPs ( vaso - active intestinal
peptides)
3. Abnormality of intestinal motility :
e.g. Thyrotoxicosis, IBS, D neuropathy.
4. Abnormality of intestinal mucosa : e.g. inflammation.

8.  H2O _ dehydration.
 K _ hypokalemia.
 HCO3 _ Acidosis.

9. 1- History analysis:
 Frequency: >4/d _ diarrhea
- If the stool is of large volume & not excessive frequent
small bowel disease.
- If the stool is of small volume & excessive frequent
large bowel disease.
 Consistency: - watery: inflammation
- greasy: malabsorption.
 Color of stool: - bloody as in ulcerative colitis.
- pale as in steatorrhea.
– tarry as in melena.
 Relation to meal:

10. Associated symptoms:
• Abdominal pain: all causes of diarrhea except
drug induced & Thyrotoxicosis.
• Nausea & vomiting: Acute infections.
• Fever: infection, inflammation.
• Constipation: IBS.

11. 2- Examination:
 abdominal tenderness
 bowel sounds
 degree of general hydration
 examination per rectum: to exclude rectal
mass or blood.

12. 3- Investigations: 4 S
Not every patient who presents with diarrhea needs to be
evaluated with these expensive tests, watchful waiting &
symptomatic therapy with oral fluid are very enough.
 Stool examination: - for ova, cysts & parasites.
- stool osmolarity - fat assay.
 Sigmoidoscopy: if a large bowel cause is suspected.
 Small bowel radiology: if a small bowel cause is suspected.
 Serological tests.
 Plus Investigations of malabsorption syndrome.

13. Prevention
Treatment
 Specific : treatment of the cause.
 Symptomatic:
- Anti diarrhea : Diphenoxylate ( lomotil ) , Loperamide (
loperazine )
- Anti emetic: motilium
 Supportive:
- Diet: _ avoid fat, _ irritants , light diet.
- Treatment of complications: Fluid – K – HCO3 .

15.  Cholera is an acute diarrheal illness caused by infection
of the intestine with the bacteria Vibrio cholerae.

16. •Gram negative.
•Type of Gammaproteobacteria
•Distinguishing factors:
•Oxidase-positive,
•motile via polar flagellum, and
both respiratory and fermentative
metabolism.
•Organism can multiply freely in
water

17. Drinking
contaminat
ed water.
eating raw
or
undercook
ed shellfish

18. • Rare in developed countries
• Common in Asia, Africa, & Latin America
Poor sanitary
conditions
• Contaminated seafood, even in developed
countries.
• Especially shellfish.
Raw or
undercooked food
• People with low levels of stomach acid
• Such as children, older adults, and some
medications.
Hypochlorhydria
• Reasons aren't entirely clear
• Twice more likelyType O blood

19. V. cholerae
accumulates in
stomach
Produces toxins
Toxins will bind
to G-protein
coupled receptor
Inactivation of
GTPase
G- protein stuck
in "on" position
increase cAMP
activation of ion
channels
NaCl influx into
intestinal lumen
to drag water
into lumen
lead to watery
diarrhea

20.  Most people remain asymptomatic. The symptoms of
cholera include :
profuse, watery
diarrhea
stomach
pains
leg cramps Mild fever
Vomiting Sunken eyes
and cheeks
Dry mucous
membranes
Decreased
urinary output
Incubation period is 24-48 hours.

21. severe dehydration Shock
Renal failure Death

22. Clinical diagnosis
Cholera should be considered
in all cases with severe watery
diarrhea and vomiting.
Traveling to affected areas and
eating shellfish
No distinguishing clinical
manifestations for cholera.
Differential diagnosis
Enterotoxigenic e. Coli
Bacterial food poisoning
Viral gastroenteritis

23. •Vibrios often detected by dark
field or phase contrast
microscopy of stool
•Organisms are motile,
appearing like “shooting stars”
•Microscopy show sheets of
curved Gram negative rods.
•When plated on sucrose dishes,
yellow colonies appear
confirming cholera present

24.  Additional methods of detection include
PCR and monoclonal antibody-based
stool tests.

25. Oral rehydration salts
• Up to 80% of cases can be treated through this.
Intravenous fluids (Ringer lactate)
• For severe cases.
Antimicrobial Therapy
• can diminish duration of diarrhea, reduce volume
of rehydration fluids needed, and shorten duration
of V. cholerae excretion.

26. DRUG THERAPY
The goals of drug therapy are to eradicate
infection, reduce morbidity and prevent
complications.
The drugs used for adults include
tetracycline, doxycycline, cotrimoxazole &
ciprofloxacin.
For children erythromycin, cotrimoxazole
and furazolidone are the drugs of choice.

27. • Basic health education and hygiene
• Mass chemoprophylaxis
• Provision of safe water and sanitation
• Comprehensive Multidisciplinary
Approach: water, sanitation, education, and
communication

28. Parenteral Vaccine :
• 2 doses administered 2 weeks apart
• Efficacy of approximately 50% and hardly exceeds 6 months
• Not recommended
Killed WC/rBS Vaccine :
• Killed whole-cell V.cholerae in combination with a recombinant B-subunit of cholera toxin
• Safe in pregnancy and breastfeeding
• Efficacy of approximately 50% after 3 years
• Only mild side-effects
Live, attenuated CVD 103-HgR Vaccine :
• Protection as early as 1 week after vaccination, with >90%
• Unknown efficacy for children under 2
• No adverse side-effects