Loose or frequent stools lasting more than 4 weeks.
Common causes
• Functional (IBS-D)
• Inflammatory (IBD: Crohn’s, UC)
• Infectious (Giardia, C. difficile)
• Malabsorption (celiac disease, pancreatic insufficiency)
• Medication side effects
Evaluation
• Stool studies (culture, O&P, calprotectin)
• Blood tests (CBC, electrolytes, inflammatory markers)
• Endoscopy or colonoscopy with biopsies if indicated
Treatment
• Diet: low-FODMAP, lactose-free, tailored to cause
• Medications: loperamide, cholestyramine, budesonide for microscopic colitis
• Address underlying condition (antibiotics, immunomodulators)
Afterwards
• Monitor hydration and electrolytes
• Nutritional supplementation if malabsorption present
Follow-up
• Reassess symptoms and labs in 4–6 weeks
• Adjust therapy based on response
