DIARRHOEA OVERVIEW

·         Any intestinal pathology causing malabsorption or steatorrhoea may cause diarrhoea.

·         Alternatively, diarrhoea itself MAY result in malabsorption & steatorrhoea

OSMOTIC DIARRHOEA	SECRETORY DIARRHOEA
·         Due to osmotic pressure exerted by the non-absorbed dietary substances present in the intestine	·         Due to electrolyte secretion
·         On prolonged fasting (>24 hrs) stool output ↓	·         No change in stool output on prolonged fasting
·         Stool osmolar gap >50	·         Stool osmolar gap <25

STOOL OSMOLAR GAP

2×(Stool[Na⁺] + Stool[K⁺]) ≤ Stool Osmolality

·         If stool osmotic gap ↑ = ↓ (Stool[Na⁺] + Stool[K⁺]) & their corresponding anions

·         Stool osmolality in diarrhea= 300 mosm/kg