Crohn’s disease is a chronic, nonspecific inflammatory disease with a risk of recurrence. Patients with Crohn’s disease enter remission after drug treatment with comprehensive assessment of clinical symptoms, laboratory tests, and endoscopic performance, during which Crohn’s disease-related symptoms appear again, called Crohn’s disease relapse, with the following symptoms: 1. abdominal pain, diarrhea, palpable abdominal masses, and weight loss; 2. extra-intestinal manifestations of Crohn’s disease, such as multiple oral ulcers, joint pain, and fistula formation; 3. blood tests Blood tests and C-reactive protein were found to suggest an inflammatory response; 4. Endoscopy revealed the presence of segmental, fissure-like ulcers again. Endoscopy is relatively sensitive in general, so it is often used to monitor for recurrence, but in the end, it is a combination of various tests to assess whether there is recurrence.