MRCP2-2082

A 40-year-old woman with a history of Crohn’s disease presented to the gastroenterology clinic with complaints of tiredness, loose stools, persistent abdominal pains, bloating, and weight loss of approximately 4kg over the past 8 months. Despite a trial of mebeverine and loperamide, her symptoms persisted. On examination, she appeared pale but otherwise well. Investigations revealed low Hb, high MCV, high platelets, low B12, and high folate levels. Gastroscopy and colonoscopy were normal, but capsule endoscopy showed jejunal strictures and fistulae. The Schilling test showed 1% B12 isotope excretion before and after administration of intrinsic factor. What is the most likely diagnosis?