Diarrhea Biochemically,diarrhea is a disturbance in intestinal electrolyte and water transport. Under normal circumstances the intestinal epitheliums is able to maintain balance between secretion and absorption. The villous epithelium absorbs water and sodium ions while the crypt epithelium secretions water and chloride ions How do anti-diarrhoeal agents work?i anti-diarrhoeal agents may exert beneficial effects via four distinct mechanisms i 1) antimicrobial activity against any offending micro-organisms i 2) stimulation of absorption of water and electrolytes i3) decrease stimulated water and anion secretion i4)claim activity for agents such as kaolin is that of physical adsorption and inactivation of toxins and microbes Why do rehydration solutions help?i Rehydration fluids produce a beneficial effect in diarrhea by increasing water absorption What causes traveler's diarrhea?i Infection by pathogenic strains of Escherichia coli (E.coli). the pathogenic strains of Escherichia coli (E.coli) can be identified by their ability to produce enter toxins and /or to attach themselves to the intestinal wall and to invade the epithelial cells. Salmonella , campylobacter , giardia and Entamoeba histolytica How does loperamide work?i Loperamide(Imodium®) is structurally related to the opiates but it is free of their narcotic activity . the drug binds to opiate receptors much like codeine and decreases intestinal activity . the drug also inhibits prostaglandin E2 induced secretion of water and electrolyte. LoperamideHcl 2mg/capsule LoperamideHcl 0.2mg/1ml