1. Diarrhea

2. Defined as bowel movements which are excessive in volume, frequency, or liquidity. Frequency & consistency of fecal discharge are variable among individuals. Diarrhea results from an imbalance in absorption & secretion of water & electrolytes. If absorption of water in the small bowel & colon ↓ or secretion ↑ above normal → diarrhea results.

3. Clinical presentations: Generally: –Dehydration. –Malnutrition. –Wt loss. –Special vitamin deficiency. In young children: high mortality rate is encountered with gastroenteritis.

4. Causes of diarrhea: – Infections (viral or bacterial). – Motility disorder, e.g. DM / postsurgical. – Drug induced, e.g. laxative abuse.

5. Pathophysiology  Change in active ion transport by either ↓ Na + absorption or ↑ Cl - secretion.  A change in intestinal motility.  An ↑ in luminal osmolarity.

6. Types of diarrhea Secretary diarrhea: secretogogues maintain ↑ rates of fluid & electrolytes secretion or ↓ absorption. Osmotic diarrhea: poorly absorbable substances retain intestinal fluids. Exudative diarrhea: diarrhea associated with discharge of mucus, protein, or blood in the gut.