A 2-year-old child presents with acute watery diarrhea and moderate dehydration (10% fluid loss). Oral rehydration therapy is planned. Which is the drug of choice for antimotility in this child?

Explanation

## Antimotility Agents in Acute Diarrhea **Key Point:** Antimotility agents are contraindicated in acute infectious diarrhea in children, particularly those with fever, bloody stools, or suspected invasive pathogens (Shigella, Salmonella, Campylobacter, E. coli O157:H7). ### Why Antimotility Agents Are Avoided 1. **Risk of Toxic Megacolon** — Slowing intestinal transit in invasive bacterial diarrhea increases mucosal contact time with toxins and bacteria, raising the risk of fulminant colitis and toxic megacolon. 2. **Prolonged Bacterial Shedding** — Reduced motility extends the period of pathogen excretion and systemic absorption of endotoxins. 3. **Increased Hemolytic Uremic Syndrome (HUS) Risk** — Particularly with Shiga toxin–producing E. coli (STEC); antimotility agents increase toxin absorption and HUS incidence. 4. **Encephalopathy Risk** — In Shigella dysentery, antimotility agents worsen CNS complications. ### Correct Management **High-Yield:** The drug of choice for acute diarrhea in children is **supportive care with ORS (oral rehydration solution)** and continuation of age-appropriate feeding. No antimotility agent is indicated. - **ORS composition:** WHO-UNICEF low-osmolarity formula: Na^+^ 75 mmol/L, Cl^−^ 65 mmol/L, glucose 75 mmol/L, K^+^ 20 mmol/L, HCO~3~^−^ 10 mmol/L. - **Zinc supplementation:** 10–14 mg/day for 10–14 days reduces duration and severity of diarrhea and prevents recurrence for 2–3 months. - **Probiotics:** Lactobacillus GG may reduce duration by 1 day in viral diarrhea (modest benefit). ### When Antimotility Agents *Might* Be Considered Only in non-inflammatory, non-infectious diarrhea (e.g., post-infectious irritable bowel syndrome in older children) — and even then, with extreme caution and only after infectious causes are excluded. **Clinical Pearl:** In India, acute diarrhea in children is predominantly viral or due to enteroinvasive bacteria; empiric antimotility agents are never first-line and are actively harmful.