Introduction
Acute Gastroenteritis (AGE) is defined as the sudden onset of 3 or more loose or watery stools within 24 hours, often associated with vomiting, fever, or abdominal discomfort. The illness usually lasts for less than 14 days.
AGE remains a major cause of morbidity in children under 5 years of age, with dehydration being the main cause of complications and mortality.
Common Causes of AGE
1.Viral Causes (Most Common)
Rotavirus Infection
Norovirus Infection
2.Bacterial Causes
Shigellosis
Salmonellosis
Cholera
3.Parasitic Causes
Giardiasis
Pathophysiology of Diarrhea
Diarrhea mainly occurs through three mechanisms:
1. Secretory Diarrhea
Examples: Cholera, Enterotoxigenic E. coli (ETEC)
In this type, toxins stimulate intestinal secretion of water and electrolytes. This causes profuse watery diarrhea with voluminous fluid loss.
2. Invasive Diarrhea
Examples: Shigella, Campylobacter
In this type, organisms invade the intestinal mucosa and cause inflammation. This may lead to bloody stools, abdominal pain, and fever.
3. Osmotic Diarrhea
Example: Malabsorption conditions
In this type, unabsorbed substances remain in the intestinal lumen and pull water into the bowel. This results in watery diarrhea with fluid loss.
Stool Analysis Interpretation
Stool examination helps identify the likely etiology:
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5 pus cells + RBCs → Suggests bacterial dysentery with invasive infection.
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5 pus cells + No RBCs + No fever → Suggests inflammatory but minimally invasive diarrhea.
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Ova or cysts present → Suggests parasitic infection.
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Negative stool culture does not rule out viral infection or toxin-mediated diarrhea.
Case 1: Adult AGE
A 24-year-old male presented with acute diarrhea, nausea, and vomiting after consuming street food. Stool microscopy showed 6–8 pus cells with no blood.
The patient’s Hb of 10.2 g/dL represented a compensated baseline, consistent with Thalassemia minor, rather than an acute hemorrhagic event. In acute blood loss, we would expect hemodynamic instability such as tachycardia or hypotension.
The clinical focus was on rehydration, rest, and temporary review of iron supplements for 1–2 weeks to avoid GI irritation during the acute illness.
Clinical Interpretation
- Pus cells without RBCs suggested mild inflammatory or toxin-mediated diarrhea.
- Absence of fever, tenesmus, or severe abdominal pain made invasive bacterial infection less likely.
Differential Diagnosis
Viral gastroenteritis
Food-borne toxin-mediated illness
Mild bacterial enteritis
Iron supplement–related GI irritation
Management
Oral rehydration
Antiemetics if needed
Temporary review of iron supplements
Antibiotics were avoided unless red-flag signs developed
Case 2: Pediatric AGE
A 2-year-old child presented with loose stools (8 episodes/day), vomiting, and reduced urine output. There was no blood in stool.
Clinical Assessment
Hydration status was assessed first. Examination showed:
Sunken eyes
Irritability
Reduced urine output
Based on World Health Organization dehydration criteria, the child was classified as:
Acute watery diarrhea with Some Dehydration (Plan B).
Clinical Reasoning
- Absence of blood made invasive bacterial diarrhea less likely.
- Age and presentation suggested viral gastroenteritis, commonly caused by Rotavirus Infection or Norovirus Infection.
Management
ORS: 50–100 mL/kg over 4 hours.
Zinc supplementation: 20 mg once daily for 10–14 days (>6 months)
Continued breastfeeding and normal feeding
Antibiotics were avoided due to absence of invasive features.
Clinical QuestionS from Session:-
1.How long does acute gastroenteritis take to recover completely?
A participant asked how many days it usually takes for a patient with acute gastroenteritis to recover completely.
The speaker explained that recovery time depends on multiple factors, including:
Degree of dehydration ,Cause of infection, Severity of symptoms, Response to treatment.
In most cases of mild diarrhea with proper hydration and supportive treatment, recovery usually occurs within 3–7 days, and generally does not extend beyond one week.
However, recovery may take longer in cases of severe dehydration, invasive infection, or underlying medical conditions.
2.Yeast in Stool
A participant asked about the significance of yeast in stool examination. The speaker explained that if the patient has no relevant symptomsor GI complaints, yeast usually does not need clinical consideration, but it may become significant in immunocompromised patients such as those with Human Immunodeficiency Virus Infection or Diabetes Mellitus.
Red Flag Signs
Persistent Vomiting
Consider ORS, Ondansetron, and IV fluids if needed
Blood in Stool
Think of invasive bacterial diarrhea
Consider antibiotics if clinically indicated
Severe Dehydration
Signs include lethargy, sunken eyes, poor perfusion
Immediate IV fluids
Preferred fluid: Ringer’s Lactate .Avoid plain 5%dextrose.
Altered Sensorium
Suggests severe dehydration or shock
Requires immediate IV fluid resuscitation
Infants <6 Months
High-risk group
Require early rehydration and zinc supplementation
Key Learning Points
• Reduced osmolarity ORS (245 mOsm/L) is now the World Health Organization standard because lower osmolarity improves absorption and reduces vomiting.
• Antibiotics do not shorten viral diarrhea. They may alter gut flora and contribute to antimicrobial resistance.
• Antibiotics are indicated only in selected conditions such as: Dysentery
Cholera, severe sepsis.
Examples include Azithromycin and Ciprofloxacin in selected cases.
• Adjuvants such as Ondansetron and Racecadotril are optional and should never replace the fundamentals.
Dehydration Classification (WHO)
Plan A → No dehydration
Plan B → Some dehydration (signs: = Restless, irritable, sunken eyes, drinks eagerly)
Plan C → Severe dehydration (signs: = lethargic, unconscious, very sunken eyes, unable to drink)
Core Treatment Principle
ORS + Zinc + Continued Feeding = Evidence-based management of AGE
Clinical Pearls
1.Blood in stool -Think invasive bacterial diarrhea- Consider antibiotics
2.No blood in stool -Viral etiology is more likely
3.Dehydration, not diarrhea itself, is the main cause of mortality.
This session highlighted that dehydration, not diarrhea, is the real enemy.what is your go-to clinical sign to quickly distinguish between ‘Some’ and ‘Severe’ dehydration?
MBH/AB