Physiology Ingestion of osmotically active substance causes osmotic diarrhoea. Which of the following can cause osmotic diarrhea? A Disaccharidase deficiency B Phenolphthalein C Bisacodyl D Castor oil 💡 Explanation Ingestion of osmotically active substance causes osmotic diarrhoea. Which of the following can cause osmotic diarrhea? ✓ Correct Answer: A. Disaccharidase deficiency