Antidiarrheals - Anti-motility agents, Adsorbents, Fluid and electrolyte modifiers.

Diarrhea is characterized by two main factors i.e. increased motility of GI tract and decrease absorption of fluids. Antidiarrheals includes antimotility agents which decrease the movement of Gastrointestinal tract by binding to presynaptic opioid receptors of enteric nervous system present in Gut. which cause the inhibition of acetylcholine release and thus causing decrease in peristalsis. It includes Diphenoxylate and loperamide, which are analogs of meperidine (an opioid). These agents can cause megacolon so should not be used in younger ones and patients with severe colitis. At this dose these agents lack analgesic effect. Adsorbents form layer or coating on the intestinal mucosa and protect the body from absorbing toxins and includes agents like aluminium hydroxide and methylcellulose but these agents are less effective and interfere with absorption of other drugs. Agents that modify fluid and electrolyte transport includes bismuth subsalicylate, used in traveler’s diarrhea. These