An 18-year-old man presented with fever, night sweats and progressive weight loss over 2 months. He had a history of Peutz-Jeghers syndrome (PJS) complicated by previous intussusception requiring left hemicolectomy. Colonoscopy revealed deep punched out ulceration throughout the colon with multiple polyps. He was investigated for tuberculosis based on his occupation as dairy farmer. Following a negative QuantiFERON test, he was started on infliximab as emergency therapy and made a good recovery at 6 months follow-up. We describe a case of newly diagnosed Crohn's disease (CD) in an adolescent with a background diagnosis of PJS. While inflammatory bowel disease, such as CD, is common in the UK, the association with PJS is very rare, with only two existing case reports in the literature.