1. Diarrhea is conventionally defined as more than three stools,which are of abnormal liquidity per day.1 Daily fecal weight (200 g daily) 1. Jeejeebhoy KN. Symposium on diarrhea. 1. Definition and mechanisms of diarrhea. Can Med Assoc J1977;116:737-9

2. These definitions has problem Indian population9% of healthy Indian population pass 3 or more stools per dayand 90% pass 1-2 stools per day.2Average stool weight in healthy Indian adults is 311 g/d.2 3. Tandon RK, Prasad N, Gupta MC, Tandon BN. Stool weights and transit time in north Indians. Jr Asso Phys Ind1976;24:807-10 2 Ghoshal U et al. Epidemiological and clinical profile of irritable bowel syndrome in India: Report of the Indian Society ofGastroenterology Task Force. Indian J Gastroenterol 2008;27:22-8 3. Acute if 4 weeks 4. Volume (large vs. small)Pathophysiology (secretory vs. osmotic) Stool characteristics(watery vs. fatty vs. inflammatory)Epidemiology 5. Mayo Clin Proc. June2012;87(6):596-602 6. Normal recto sigmoid colon functions as a storage reservoir. Frequent small volume stools- inflammatory or motilitydisorders involving the left colon Bowel movements are less frequent and larger- right colonic orsmall bowel source 7. Intestinal malabsorption of ingested nonelectrolytes (osmoticdiarrhea) Diarrhea that results from malabsorption or secretion of electrolytes(secretory diarrhea) In secretory diarrhea, sodium, potassium, and accompanying anionsaccount almost entirely for stool osmolality In osmotic diarrhea poorly absorbable solutes within the lumen ofthe intestine account for much of the osmotic activity of stool water Abates with fasting- osmotic diarrhea. 8. Watery diarrhea implies a defect primarily in water absorptionas a result of increased electrolyte secretion or reducedelectrolyte absorption (secretory diarrhea) or ingestion of apoorly absorbed substance (osmotic diarrhea). Fatty diarrhea implies defective absorption of fat and perhapsother nutrients in the small intestine. Inflammatory diarrhea Presence of white blood cells or bloodin the stool are classified as having inflammatory diarrhea 9. APPROACH 10. Mastocytosis (urticaria pigmentosa)Amyloidosis (macroglossia, waxy papules, pinch purpura) Addisons disease (increased pigmentation)Glucagonoma(migratory necrotizing erythema) Carcinoid syndrome (flushing) 11. Celiac disease (dermatitis herpetiformis). Tremor and other systemic signs should lead to considerationof hyperthyroidism. Right-sided heart murmurs, as well as an enlarged hard liver,may be present with carcinoid syndrome. 12. Occult blood White blood cells Sudan stain for fat. Fecal cultures pH, electrolytes and minerals, and laxatives Osmotic gap 13. Tests for the neutrophil products, calprotectin and lactoferrin,are sensitive and specific for the detection of neutrophils instool and may be a useful alternative to microscopy. Routine stool cultures are of little use C. difficile toxin 14. Osmotic gap is calculated by subtracting twice the sum of the sodiumand potassium concentrations from 290 mOsm/kg, the osmolality ofstool in the body. A small osmotic gap (100 mOsm/kg) indicates that much of thestool osmolality is composed of nonelectrolytes A large gap is characteristic of an osmotic diarrhea, usually resultingfrom ingestion of some poorly absorbed substance, such asmagnesium salts. 15. The diagnostic yield of colonoscopy or sigmoidoscopy with biopsy inpatients referred for chronic diarrhea is approximately 15% to 30%. Chronic disorders that can be diagnosed by inspection of the colonicmucosa Melanosis coli Ulcerations Polyps, Tumors, IBD Amebiasis. Surawicz CM, Meisel JL, Ylvisaker T, Saunders DR, Rubin CE. Rectal biopsy in the diagnosis of Crohns disease: value of multiple biopsies and serial sectioning. Gastroenterology 1981; 80:6671. Candreviotis N. The pathology of chronic amebic colitis in Greece studied by colon biopsy. Am J Proctol 1966;17:3947. Nostrant TT, Kumar NB, Appleman HD. Histopathology differentiates acute self-limited colitis from ulcerative colitis. Gastroenterology 1987;92:318328. 16. Diseases in which the mucosa appears normal endoscopicallybut that can be diagnosed histologically Microscopic colitis (lymphocytic and collagenous colitis),AmyloidosisWhipples diseaseGranulomatous infections Schistosomiasis 17. Diseases that may be diagnosed by small intestinal biopsy Crohns disease Giardiasis Celiac sprue Intestinal lymphoma Eosinophilic gastroenteritis, Hypogammaglobulinemic sprue Whipples disease Lymphangiectasia, Abetalipoproteinemia Amyloidosis, mastocytosis, Various mycobacterial, fungal, protozoal, and parasitic infections.Rubin CE, Dobbins WO. Peroral biopsy of the small intestine. Gastroenterology 1965;49:676697. .Perera DR, Weinstein WM, Rubin CE. Small intestinal biopsy. Hum Pathol 1975;6:157217. Whitehead R. Jejunal biopsy In: Whitehead R, ed.Mucosal biopsy of the gastrointestinal tract. 3rd ed. London: Saunders, 1985:139164. 18. THANK YOU