A 42-year-old man presents to your clinic with a 6-month history of progressive epigastric pain and chronic diarrhea refractory to treatment with omeprazole 20 mg daily. He completed triple therapy for H. pylori infection 3 months ago with documented eradication by urea breath test. He denies NSAID use, alcohol abuse, or aspirin. Vital signs are stable. Upper endoscopy reveals multiple large duodenal ulcers and severe erosive esophagitis. Laboratory studies show: fasting serum gastrin 1,400 pg/mL (normal <100 pg/mL), gastric pH 1.5, and normal liver and renal function. Which of the following is the most likely diagnosis?

1. A)H. pylori reinfection with treatment-resistant strain
2. B)Medication-induced ulcer recurrence secondary to proton pump inhibitor discontinuation
3. C)Crohn disease with gastroduodenal involvement
4. D)Zollinger-Ellison syndrome from a sporadic gastrinomaGABARITO
5. E)Multiple endocrine neoplasia type 1 with gastrinoma