Crohn disease is an inflammatory disease of the digestive system that may affect the small and large intestines. Remission and recurrence clinically characterized its development. When recurrence occurs, a careful examination is necessary in order to determine the extent and the severity of the disease. Actual exams performed are invasive and uncomfortable(colonoscopy and bowel follow through). Compare to these exams, PET/CT is less fierce to undergo and has less risks. Two groups are proposed in this project: 15 patients will be enroll in the active disease group and 15 patients will be enroll in the remission group. In regards of the area and the extent of the disease,PET/CT exams shall provide similar information than what usual tests provide. PET/CT exams shall also provide more information in order to better differentiate inflammatory stenosis from scars stenosis especially located in the small intestine.