Diarrhea

Descriptive text is not available for this imageBASICS

DESCRIPTION

  • Diarrhea is defined as an increase in frequency, volume, or fluidity of a patient’s stool as compared to the normal bowel movement pattern.
  • Based on its duration, diarrhea can be classified as acute (<14 days) or chronic (>14 days).
  • Diarrhea is often determined by increased frequency of the stool; however, the assessment of stool volume and consistency is also important. It typically presents with increased fluid content of the stool volume >10 to 20 mL/kg/24 h in infants and younger children or involves the passage of >250 g/24 h of unformed stool in older children.

EPIDEMIOLOGY

  • Acute infectious diarrhea results in >1.5 million outpatient visits and 200,000 hospitalizations in the United States annually.
  • For chronic diarrhea, incidence and prevalence vary greatly depending on the underlying etiology.

RISK FACTORS

  • The risk of infectious diarrhea is higher in areas with contaminated drinking water and poor sanitation.
  • Genetic predisposition can be seen in cases of chronic diarrhea such as celiac disease, cystic fibrosis (CF), endocrine disorders, and inflammatory bowel disease (IBD).

GENERAL PREVENTION

  • The World Health Organization recommendations for prevention of infectious diarrhea:
    • Access to safe drinking water
    • Use of improved sanitation
    • Hand washing with soap
    • Exclusive breastfeeding for the first 6 months of life
    • Good personal and food hygiene
    • Health education about how infections spread
    • Rotavirus vaccination

PATHOPHYSIOLOGY

  • Secretory diarrhea
    • Absorption of intestinal fluid and electrolytes is accomplished through multiple cellular pumps transporting sodium, glucose, and amino acids.
    • Factors that interrupt these pumps (e.g., cholera toxin, prostaglandin E, vasoactive intestinal peptide, secretin, acetylcholine) can cause a severe active isotonic secretory intestinal state manifested by profuse diarrhea, dehydration, and acidosis.
  • Osmotic diarrhea
    • In general, the solute composition of intestinal fluid is similar to that of plasma. Osmotic diarrhea occurs when poorly absorbed or nonabsorbable solute is present in the intestinal lumen (this may result in low stool pH <5.5).
    • This can occur with the ingestion of nonabsorbable sugars (e.g., sorbitol), cathartics (e.g., magnesium citrate), carbohydrate malabsorption (e.g., lactose intolerance), maldigestion (e.g., pancreatic dysfunction), or rapid transit of intestinal fluid.
  • Although isolated secretory or osmotic diarrhea can be seen, most acute infectious or chronic diarrhea may have mixed secretory and osmotic mechanisms.

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