Ace the 2026 Chronic Small Intestinal Disease Exam – Digest Your Way to Success!

Mechanical or structural problems cause chronic diarrhea by directly altering the gut’s ability to absorb fluids and nutrients or by changing the transit of intestinal contents. Short bowel syndrome is a clear example: when large portions of the small intestine are removed, the remaining bowel has less surface area and altered motility, leading to poor absorption and watery, frequent stools. This contrasts with infectious causes (driven by pathogens), immune‑mediated inflammatory diseases (mucosal inflammation), or vascular disorders (ischemia-related issues) which are not primarily about a fixed structural loss or disruption of the absorptive surface. Thus, short bowel syndrome best fits the category of mechanical/structural chronic diarrheal causes.