osmotic diarrhea

Etiology

• lactase deficiency (most common)
  • may occur secondary to recent food poisoning or gastroenteritis
• fructose malabsorption

Clinical manifestations

• associated with eating
• responds to fasting
• generally, not nocturnal
• lesser stool volumes than secretory diarrhea (< 1 L/day)

Laboratory

• stool osmolality > 340 mOsm/kg
• fecal osmotic gap > 100 mOsm/kg

Management

• withdrawal of osmotically active agent
• lactase deficiency: avoid lactose
• - fructose malabsorption: avoid fructose

More general terms

• diarrhea