Source / episode info

• **Episode:**214
• **Title:**Divine Intervention Episode 214 – Family Medicine Shelf Review Series 5 (GI Final).
• **Published:**2020-02-28
• Source:Episode page

One-liner

This episode provides a comprehensive review of chronic diarrhea etiologies, covering infectious agents (Giardia, Cryptosporidium), malabsorptive states (Celiac disease, Tropical Sprue), inflammatory conditions (Crohn's vs. UC), and functional disorders (IBS), emphasizing diagnostic workup and management pitfalls.

High-yield summary

• Diarrhea Classification: Stool Osmolar Gap is key: High gap (>100 mOsm/kg) suggests osmotic diarrhea (e.g., lactase deficiency); Low gap (<50 mOsm/kg) suggests secretory diarrhea (e.g., Cholera, VIPoma).
• Infectious Agents: Giardia and Cryptosporidium are common causes of chronic watery diarrhea in travelers; C. difficile requires a history of recent antibiotic use or hospitalization.
• Malabsorption Syndromes: Celiac disease is strongly associated with other autoimmune conditions (Type 1 Diabetes, Hashimoto's) and can lead to fat malabsorption, microcytic anemia, and dermatitis herpetiformis.
• IBD Differentiation: Crohn's disease typically presents with skip lesions and transmural inflammation; Ulcerative Colitis (UC) is continuous and involves the rectum first. Both carry risks of extra-intestinal manifestations (arthritis, uveitis).
• Safety Pearls: Never administer anti-motility agents (like Loperamide/Diphenoxylate) to patients with suspected EHEC or C. difficile infection due to increased risk of Hemolytic Uremic Syndrome (HUS) or Toxic Megacolon.

Learning objectives

• Differentiate the clinical presentations and pathological findings of Crohn's disease versus Ulcerative Colitis.
• Interpret stool studies, specifically distinguishing between osmotic and secretory diarrhea based on the osmolal gap.
• Identify key associations in malabsorption syndromes (e.g., Celiac disease with autoimmune disorders).
• Recognize the appropriate management steps for acute infectious gastroenteritis while avoiding iatrogenic complications (e.g., Loperamide use).
• Understand the differential diagnosis of chronic diarrhea, including functional and tropical causes.

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