**Question:** A 43-year-old woman has had a 10-year history of severe and recurrent peptic ulcer disease (PUD) that is refractory to medical therapy. She has had ulcers at multiple sites of the small bowel including the distal duodenum and jejunum. She also has chronic diarrhea, but not enough fat to make the diagnosis of steatorrhea. Evaluation for Helicobacter pylori infection is negative. For the above patient with GI symptoms, select the possible diagnoses and associated findings.

A. Crohn's disease
B. Zollinger-Ellison syndrome
C. Villous adenoma
D. Inflammatory bowel disease (IBD)

**Correct Answer:** B. Zollinger-Ellison syndrome

**Core Concept:**

Peptic ulcer disease (PUD) is a condition characterized by the formation of open sores or ulcers in the gastrointestinal tract, primarily affecting the stomach and the duodenum. In this case, the patient has recurrent PUD refractory to medical therapy, and ulcers at multiple sites in the small bowel. The presence of chronic diarrhea without steatorrhea suggests a condition with increased intestinal secretion rather than malabsorption.

**Why the Correct Answer is Right:**

Zollinger-Ellison syndrome (ZES) is a rare condition characterized by the coexistence of gastric ulcers and hypersecretory conditions, typically caused by the presence of gastrin-secreting tumors (Zollinger cells) in the pancreas or duodenum. In this case, the patient's small bowel ulcers and persistent gastric ulcers despite medical therapy point towards an underlying cause for the excessive gastric secretion.

**Why Other Options are Incorrect:**

A. Crohn's disease (CD) is a type of inflammatory bowel disease (IBD) that involves transmural inflammation of the gastrointestinal tract. While CD can also cause ulcers, it is less likely given the patient's small bowel ulcers and gastric ulcers resistant to treatment.

C. Villous adenoma is a benign tumor of the gastrointestinal tract, particularly common in the colon, but less likely in the small bowel and associated with ulcers.

D. IBD is a broad term for a group of diseases that cause chronic inflammation of the gastrointestinal tract, which may or may not lead to ulcers. However, Zollinger-Ellison syndrome (ZES) is more specific, involving excessive gastric secretion due to gastrin-secreting tumors. Hence, ZES is the most likely diagnosis in this case.