II. Epidemiology

  1. Incidence
    1. U.S. Outpatient Visits: 1.5 Million per year
    2. U.S. Hospitalizations: 200,000 per year
    3. Deaths
      1. U.S.: 300 per year
      2. World: 2.5 Million per year (age under 5 years)
        1. Fifth leading cause of death in children worldwide)

III. Definitions: Diarrhea

  1. See Pediatric Vomiting
  2. General
    1. See Diarrhea
    2. Sudden increased stool frequency and looseness
    3. Three or more watery or loose stools per day
  3. Types
    1. Non-Inflammatory Diarrhea
      1. Watery stools without blood or mucus
      2. Small Intestine involvement without mucosa destruction
    2. Inflammatory Diarrhea
      1. Bloody stools with mucus (Stool Leukocytes)
      2. Large Intestine involvement
      3. Associated with fever, vomting and abdominal tenderness
  4. Severe Diarrhea by frequency (inaccurate, use degree of Dehydration status to grade severity)
    1. Any Age
      1. Stools hourly for >5 hours
    2. Age under 1 year
      1. Stools >9 in 24 hours
    3. Age 1-2 years
      1. Stools >14 in 24 hours
    4. Age >2 years
      1. Stool >19 in 24 hours
  5. Green Stools
    1. Suggests very rapid transit
    2. Seen in moderate to severe Diarrhea

IV. Causes

  1. See Infectious Diarrhea Causes
  2. Viruses (75-90% of cases)
    1. Rotavirus (most common)
      1. Fever in 50% of cases
      2. Age 5 years most typically affected
      3. Most cases occur in winter
      4. Fecal Leukocytes present in 12% of cases
    2. Norovirus or Norwalk Virus
      1. No associated fever
      2. Occurs November to April in 80% of cases
    3. Enteric Adenovirus
    4. Astrovirus
  3. Bacteria (10-20% of cases, especially Inflammatory Diarrhea)
    1. Escherichia coli
      1. Accounts for 10% of Bacterial Diarrhea
      2. Fever in 20% of cases
      3. Most common in Summer
    2. Campylobacter jejuni
      1. Fever in 80% of cases
      2. Occurs all year but peaks in July
      3. Bloody Diarrhea with Fecal Leukocytes
    3. Salmonella
      1. Bloody Diarrhea
    4. Shigella
      1. High fever (and Febrile Seizures)
      2. Bloody Diarrhea
    5. Yersinia enterocolitica
    6. Clostridium difficile
  4. Parasites (<5%, especially cases lasting >14 days)
    1. Giardia lamblia
      1. No associated fever
    2. Cryptosporidium
      1. Associated with fever

V. History

  1. Onset and Duration of Diarrhea
  2. Fever and associated symptoms
  3. Emesis Frequency and character
    1. Bilious Emesis
  4. Stool Frequency and Character
    1. Watery stools
    2. Foamy stools
    3. Bloody stools
  5. Urinary output (minimums listed below)
    1. Infant: Three or more times per day
    2. Child: Two or more times per day
  6. Feeding history
    1. Oral Rehydration Solution use prior to evaluation
  7. Mental status (Behavior and activity)
  8. Recent Medications
    1. Antibiotics in the last 3 months
  9. Possible ingestions
  10. Contagious contacts
  11. Recent travel
  12. Pet exposure

VI. Symptoms: Red Flags

IX. Labs

  1. See Pediatric Dehydration
  2. Labs are not indicated in most cases of mild to moderate Diarrhea
  3. Indications
    1. Severe Diarrhea or Inflammatory Diarrhea (blood, mucous)
    2. Moderate to severe Dehydration
    3. Immunocompromised
    4. Suspected Sepsis
  4. Basic chemistry panel
    1. Serum Sodium
    2. Serum Potassium
    3. Serum Glucose
    4. Serum Creatinine
    5. Serum bicarbonate
      1. Level >15 mEq/L correlates with <5% Dehydration
  5. Fecal specimen tests (consider when specifically indicated)
    1. Stool Ova and Parasites (and GiardiaAntigen)
      1. Consider for persistent or recurrent Diarrhea lasting longer than 2 weeks
      2. Consider for travel to endemic regions
    2. Clostridium difficile Toxin B
      1. Consider if recent antibiotics or other Clostridium difficile risk factors
    3. Rotavirus
      1. Define start of an epidemic
      2. Define the cause when considering more serious possibilities
    4. Direct fecal smear for Stool Leukocytes
      1. Rarely indicated
      2. Gross blood or Fecal Occult Blood has similar sensitivity for Inflammatory Diarrhea
    5. Stool enteric pathogen PCR or NAT panel (specific organisms included varies by manufacturer)
      1. Campylobacter
      2. Salmonella
      3. Shigella
      4. Vibrio
      5. E. coli
      6. Norovirus
      7. Rotavirus
    6. Stool Culture
      1. Rarely indicated due to low Test Sensitivity

XI. Prevention

  1. See Water Disinfection
  2. See Traveler's Diarrhea Prevention
  3. See Foodborne Illness Prevention
  4. Rotavirus Vaccine (Rotarix, RotaTeq)
    1. Safe, effective oral Live Vaccine
    2. Three dose Vaccine part of the Primary Series in the first year of life in the United States

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