American Board of Internal Medicine (ABIM) Certification Practice Exam

What distinguishing feature is associated with secretory diarrhea?

1. It is relieved by fasting

2. It involves significant mucus production

3. It often leads to steatorrhea

4. It does not stop with fasting

The correct answer is: It does not stop with fasting

Secretory diarrhea is characterized by the capacity of the intestines to secrete more fluid than what can be reabsorbed, leading to excessive watery stools. A primary distinguishing feature of secretory diarrhea is that it continues regardless of fasting. This is because the underlying mechanisms driving this type of diarrhea—such as increased secretion of electrolytes and water due to pathogens, certain medications, or specific intestinal disorders—are not dependent on the presence of food in the digestive system. In contrast, osmotic diarrhea typically improves with fasting, as the osmotic load is removed when food intake ceases. The persistent nature of secretory diarrhea—even when the individual has not eaten—underscores its independence from dietary intake, which is critical in distinguishing it from other forms of diarrhea.