1. Diarrhea Definition increase in the frequency of bowel movements increase in the frequency of bowel movements increase in stool liquidity increase in stool liquidity in some cases increase in daily stool weight (>200g/d) in some cases increase in daily stool weight (>200g/d)

2. Pathophysiological mechanisms secretory diarrhea (increased intestinal secretion) secretory diarrhea (increased intestinal secretion) Osmotic diarrhea Osmotic diarrhea Decreased intestinal surface area and/or intestinal absorption Decreased intestinal surface area and/or intestinal absorption Rapid transit of intestinal contents (shortened transit time) Rapid transit of intestinal contents (shortened transit time)

3. Pathophysiological mechanisms secretory diarrhea (increased intestinal secretion) 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 

4. Pathophysiological mechanisms Osmotic diarrhea 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

6. Causes of diarrhea in enteral nutrition

7. Pathophysiological mechanisms Decreased intestinal surface area and/or intestinal absorption Decreased intestinal surface area and/or intestinal absorption E: surgical removal; malabsorption syndrome

8. Pathophysiological mechanisms Rapid transit of intestinal contents (shortened transit time) 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

9. Calculation of osmotic gap

10. Etiology Acute Diarrhea infection infection Food poisoning Food poisoning Systematic diseases (influenza, sepsis, measle, etc) Systematic diseases (influenza, sepsis, measle, etc) Miscellanous Miscellanous

11. Etiology Acute Diarrhea infection infection (A) viral (B) bacterial  campylobacteria  Shigella  E. Coli  Salmoneila  etc (C) fungal (D) parasitic (amebic Trophozoites, Giardia)

12. Food poisoning Food poisoning bacterial, plants, chemical poison(arsenic,...) bacterial, plants, chemical poison(arsenic,...) Systematic diseases (influenza, sepsis, measle, etc) Systematic diseases (influenza, sepsis, measle, etc) Miscellanous Miscellanous Allergic diseases Allergic diseases Allergic purpura, enteropathy.. endocronic diseases (ZES, etc.) endocronic diseases (ZES, etc.) Drugs: laxatives, 5-Fu, etc. Drugs: laxatives, 5-Fu, etc.

13. Etiology Chronic Diarrhea Intestinal Intestinal Gastric(chronic gastritis,subtotal gastrectomy, etc.) Gastric(chronic gastritis,subtotal gastrectomy, etc.) Pancreatic (Chronic Pancreatitis, Pancreatic Cancer, etc.) Pancreatic (Chronic Pancreatitis, Pancreatic Cancer, etc.) Hepatobiliary(liver cirrhosis, obstructive jaundice) Hepatobiliary(liver cirrhosis, obstructive jaundice) Endocronic (Hyperthyroids crisis, ZES, Carcinoids) Endocronic (Hyperthyroids crisis, ZES, Carcinoids) Drugs (Reserpin, Ismelin, Laxatives, etc.) Drugs (Reserpin, Ismelin, Laxatives, etc.) Others (uremia, hypogammaglobulemia, etc.) Others (uremia, hypogammaglobulemia, etc.)

14. Chronic Diarrhea Intestinal Intestinal infections(T.B., Chronic bacteria dysentery, etc.) infections(T.B., Chronic bacteria dysentery, etc.) parasitics (Amebia dysentery, Giardiasis, etc.) parasitics (Amebia dysentery, Giardiasis, etc.) IBD (ulcerative colitis, Chron ’ s, etc.) IBD (ulcerative colitis, Chron ’ s, etc.) malabsorption synd. (lactase deficiency, etc.) malabsorption synd. (lactase deficiency, etc.) tumors tumors

15. Mechanisms and causes of secretory diarrhea

16. Endoscopic image: infectious colitis in 7-year-old girl