Which of the following is NOT an anatomical cause of chronic diarrhea in the small bowel?

• A. Inflammatory bowel disease
• B. Intestinal obstruction
• C. Short bowel syndrome
• D. Resection of ileocolic junction

Answer: (D)

Chronic diarrhea from the small bowel typically stems from structural or mucosal problems directly affecting the small intestine’s ability to absorb fluids and nutrients. Inflammatory bowel disease damages the mucosa of the small bowel, impairing absorption and leading to chronic diarrhea. Intestinal obstruction is a fixed anatomical lesion within the small bowel that disrupts flow and can produce diarrhea from increased secretions and altered transit. Short bowel syndrome results from a loss of absorptive surface in the small intestine, causing malabsorption and ongoing diarrhea. Resection of the ileocolic junction, while it can influence appearance of symptoms by altering the transition between ileum and colon, is a surgical alteration at a boundary with the colon and does not represent a primary small-bowel anatomical cause of chronic diarrhea.