Diarrhea Definition increase in the frequency of bowel movements increase in stool liquidity in some cases increase in daily stool weight >200g/d)
Diarrhea Definition • increase in the frequency of bowel movements • increase in stool liquidity • in some cases increase in daily stool weight (>200g/d)
Pathophysiological mechanisms secretory diarrhea(increased intestinal secretion) Osmotic diarrhea Decreased intestinal surface area and/or intestinal absorption Rapid transit of intestinal contents(shortened transit time)
Pathophysiological mechanisms • secretory diarrhea (increased intestinal secretion) • Osmotic diarrhea • Decreased intestinal surface area and/or intestinal absorption • Rapid transit of intestinal contents (shortened transit time)
Pathophysiological mechanisms secretory diarrhea (increased intestinal secretion) active Adenylate CAMP NaCI↑ agents secretory cyclase system diarrhea .s infections(cholera toxin, E-col, salmonella, staphylococcal) 今 Hormonal( Gut hormones,ZES,ⅤmP), cancer(calcitonin, Prostaglandins) . o miscellaneous(laxatives abuse, villous adenoma of the rectum)
Pathophysiological mechanisms • secretory diarrhea (increased intestinal secretion) ❖ infections (cholera toxin, E-col, salmonella, staphylococcal) ❖ Hormonal (Gut Hormones, ZES, VIP), cancer (calcitonin, Prostaglandins) ❖ miscellaneous (laxatives abuse, villous adenoma of the rectum) agents Adenylate cyclase cAMP system secretory diarrhea active NaCl
Pathophysiological mechanisms Osmotic diarrhea It caused by accumulation of the followings in the gut lumen being osmotically active poorly absorble solutes maldigestion of ingested food water failure to transport an osmotically diarrhea active dietary nonelectrolyte salts (E: glucose) intestinal lumen
Pathophysiological mechanisms • Osmotic diarrhea It caused by accumulation of the followings in the gut lumen water salts poorly absorble solutes maldigestion of ingested food failure to transport an osmotically active dietary nonelectrolyte (E: glucose) intestinal Lumen being osmotically active diarrhea
Colon Short-chain fatty acids Small Intestine Fluid Carbohydrates Protein Lipids lleum Fat-soluble vitamins Folate Bile acids Vitaronbn2 Calcium, phosphorus Iron Zinc
Causes of diarrhea in enteral nutrition Lumen Intestinal mucosa Excess volume Edema Osmotic load Disaccharidases or Formulas transport mechanisms Medication Atrophy Contamination Bacteria
Causes of diarrhea in enteral nutrition
Pathophysiological mechanisms Decreased intestinal surface area and/or intestinal absorption E: surgical removal; malabsorption syndrome
Pathophysiological mechanisms • Decreased intestinal surface area and/or intestinal absorption E: surgical removal; malabsorption syndrome
Pathophysiological mechanisms Rapid transit of intestinal contents(shortened transit time) increase in intestinal motility(intestinal hurry) contents reduce volume contact time->increase liquidity, stool small bowel mucosa E: irritable bowel syndrome [Functional diarrhea laxatives abuse post vagotomy diarrhea post gastrectomy dumbing syndrome
Pathophysiological mechanisms • Rapid transit of intestinal contents (shortened transit time) E: irritable bowel syndrome [Functional diarrhea] laxatives abuse post vagotomy diarrhea post gastrectomy dumbing syndrome stool volume liquidity contact time→ increase small bowel mucosa contents increase in intestinal motility (intestinal hurry) reduce
Calculation of osmotic gap 290 Unmeasured osmoles INcO □c 200 匚aK+ 匚Na+ E 100 0 Secretory diarrhea Osmotic diarrhea Osmotic gap 290 290 2X(Na+]+〖K+])=102X(Na+]+[K+])=230
Calculation of osmotic gap
Etiology Acute Diarrhea infection Food poisoning Systematic diseases(influenza, sepsis, measle, etc) Miscellanous
Etiology Acute Diarrhea • infection • Food poisoning • Systematic diseases (influenza, sepsis, measle, etc) • Miscellanous