225 Diarrhoea
Patient 1
Patient 2
Questions
Advanced-level questions
What are the mechanisms of diarrhoea?
• Osmotic diarrhoea: the mucosa of the gut acts as a semipermeable membrane; the diarrhoea stops when the patient fasts (e.g. diarrhoea from magnesium sulfate, lactulose, malabsorptive states)
• Secretory diarrhoea: there is active secretion of intestinal fluid (e.g. Escherichia coli diarrhoea)
• Inflammatory diarrhoea: there is mucosal damage (e.g. shigellosis, ulcerative colitis)