PLAB-0375

A 19-year-old male presents with a 1-year history of diarrhoea as well as abdominal discomfort. He has 10 episodes of loose stools per day and 3 episodes of loose stools per night. He reports weight loss in the past few months. On examination of the abdomen, tenderness was present in the right lower quadrant. Endoscopy revealed cobblestone mucosa in the ileum. Which of the following conditions is he most likely suffering from?