Diarrhea (peds)

This page is for pediatric patients. For adult patients, see: diarrhea

Background

Gasterointestinal anatomy.

Layers of the Alimentary Canal. The wall of the alimentary canal has four basic tissue layers: the mucosa, submucosa, muscularis, and serosa.

• 85% of diarrhea is infectious in etiology
  • Viruses cause vast majority of infectious diarrhea
  • Bacterial causes are responsible for most cases of severe diarrhea
    • Foreign travel associated with 80% probability of bacterial diarrhea (see Traveler's Diarrhea)

Definitions

• Diarrhea: Increased frequency of defection, usually >3 bowel movements per day
• Hyperacute: 1-6 hr
• Acute: less than 3 weeks in duration
• Gastroenteritis: Diarrhea with nausea and/or vomiting
• Dysentery: Diarrhea with blood/mucus/pus
• Invasive = Infectious

Clinical Features

Bristol Stool Chart.

History

• Possible food poisoning?
  • Symptoms occur within 6hr
• Does it resolve (osmotic) or persist (secretory) with fasting?
• Are the stools of smaller volume (large intestine) or larger volume (small intestine)
• Fever or abdominal pain? (diverticulitis, gastroenteritis, IBD)
• Bloody or melenic?
• Tenesmus? (shigella)
• Malodorous? (giardia)
• Recent travel? (Traveler's Diarrhea)
• Recent antibiotics? (C. diff)
• HIV/immunocompromised/high risk behaviors?
• Heat intolerance and anxiety? (thyrotoxicosis)
• Paresthesias or reverse temperature sensation? (Ciguatera)

Physical Exam

• Thyroid masses
• Oral ulcers, erythema nodosum, episcleritis, anal fissure (IBD)
• Reactive arthritis (Arthritis, conjunctivitis, urethritis)
  • Suggests infection with salmonella, shigella, campylobacter, or yersinia

Differential Diagnosis

Infection

• Viral
  • Rotavirus
  • Norovirus, Norwalk virus
  • Enterovirus
  • Adenovirus
• Bacterial
  • Salmonella
  • Shigella
  • Yersinia
  • Campylobacter
  • Escherichia coli
  • Vibrio species
  • Clostridium difficile
  • TB
• Parasitic
  • Giardia
  • Entamoeba
  • Cryptosporidium

Dietary disturbances

• Overfeeding
• Food allergy
• Starvation stools

Anatomic abnormalities

• Intussusception
• Hirschsprung's disease
• Partial SBO
• Appendicitis
• Blind loop syndrome
• Intestinal lymphangiectasia
• Short bowel syndrome

Malabsorption or secretory diseases

• Cystic fibrosis
• Celiac disease
• Disaccharidase deficiency
• Secretory neoplasms

Systemic diseases

• Immunodeficiency
• Endocrinopathy
  • Hyperthyroidism
  • Hypoparathyroidism
  • Congenital adrenal hyperplasia

Miscellaneous

• Inflammatory bowel disease
• Antibiotic-associated diarrhea
• Secondary lactase deficiency
• Irritable colon syndrome
• Neonatal abstinence syndrome
• Toxins
• Hemolytic uremic syndrome (HUS)

Management

General Treatment

• Reduced-osmolarity oral rehydration solution
• If bloody diarrhea, use caution with beginning antibiotics in ED before stool culture results
• Some studies demonstrate antibiotic treatment in setting of E.coli O157:H7 leads to increasing risk of hemolytic uremic syndrome (HUS)

Diarrheal Pathogens in Children and Specific Therapy

AGENT	SPECIFIC THERAPY BEYOND SUPPORTIVE CARE
Campylobacter jejuni	Azithromycin 12mg/kg/day PO for 5 days or
	Erythromycin 30–50mg/kg/day, divided, tid PO for 5–7 days
Clostridium difficile	Metronidazole 30mg/kg/day, divided, QID PO for 7–10 days or
Escherichia coli	Azithromycin 12mg/kg/day PO for 5 days or
	Trimethoprim-sulfamethoxazole 10mg (TMP)/kg/day PO divided BID for 5–7 days
Giardia lamblia	Metronidazole 15mg/kg/day PO, divided, tid for 5 days
Salmonella species	In toxic infants <3 mo: Ampicillin 200mg/kg/24 hours q6h for 7–10 days and Gentamicin 5–7.5mg/kg/24 hours q8h IV
Shigella species	Azithromycin 12mg/kg/day PO for 5 days or
	Trimethoprim-sulfamethoxazole 10mg (TMP)/kg/day, divided, BID for 5–7 days if susceptible
Yersinia enterocolitica	If patient is immunosuppressed, treat as for presumed sepsis
Vibrio cholera	None; severe diarrhea or cholera may benefit from antibiotics

See Also

• Diarrhea
• Dehydration (peds)
• Nausea and vomiting (peds)
• Acute gastroenteritis (peds)