1. Age less than 2 years

• viral etiology (99%), bacterial etiology (1%)

2. Age greater than 2 years

• viral etiology (20%), bacterial etiology (80%)

1. Congenital

2. Infectious

1. Principle

• a breakdown in the balance of fluid exchange across the in-testinal mucosa resulting in an exaggerated loss of fluid (stool) through a relative increase in the secretory and decrease in the absorptive functions of the small bowel muscosa

2. Pathophysiologic Mechanisms (4)

1. Acute Diarrhea

• diarrhea
• nausea/vomiting
• fever
• abdominal pain and distension

2. Complications

Note: With secretory and cytotoxic diarrhea there may be a functional ileus with a decreased intestinal tone and slow peristaltic movement resulting in luminal dilation (abdominal pain and vomiting), delayed gastic emptying (vomiting), and marked peristaltic rushes (cramps).

1. Serum

• lytes - iso-, hypo-, hypernatremia
• increased serum osmolality
• elevated BUN with normal creatinine
• gases - metabolic acidosis
  • with an anion gap (elevated lactic acid)
  • without anion gap (bicarbonate loss in stools)

2. Urine

• specific gravity > 1.030
• ketones

3. Stools

• blood, leukocytes, reducing substances, stool pH
• C&S, viral cultures, O&P

1. Ambulatory (Oral Rehydration Therapy)

2. Admission (IV Rehydration)