A 17-year-old female presents with a 4-month history of vague abdominal pain and low-grade fever. She says she has extreme pain when she defecates. She has general malaise and arthralgia. Her abdominal radiographs are unremarkable and rectal exam is very painful. Colonoscopy revealed significant inflammation in the ileocecal area with skip lesions. Biopsy revealed transmural lesions with a neutrophilic infiltrate. What is the most likely diagnosis?