A 16-year-old girl is referred to the office because of chronic diarrhea and weight loss. She is experiencing large-volume watery diarrhea that is painless. The symptoms persist even when she is fasting, and there is no relationship to foods or liquids. She is not on any medications, and there is no travel history or other constitutional symptoms. Her physical examination is normal. Which of following is the most likely diagnosis?
High-Yield Explanation
Secretory diarrhea is caused by a derangement in fluid and electrolyte transport across the gut mucosa. The resultant diarrhea is watery, large volume, painless, and persists even when the patient fasts.