Crohn’s disease is an inflammatory disease of the intestine of unknown origin that can occur anywhere in the gastrointestinal tract, but is more prevalent in the terminal ileum and right hemicolectum. The disease and chronic nonspecific ulcerative colitis are collectively referred to as inflammatory bowel disease (IBD). The clinical manifestations of this disease are abdominal pain, diarrhea, and intestinal obstruction, accompanied by fever, nutritional disorders, and other extraintestinal manifestations. The course of the disease is prolonged, recurrent and not easily curable. The disease is also known as limited enteritis, limited ileitis, segmental enteritis and granulomatous enteritis. What tests are needed for patients with Crohn’s disease? 1. Blood tests: anemia, leukocytosis, and accelerated erythrocyte sedimentation rate are often present. 2.Fecal examination: occult blood test is often positive. 3.Gastrointestinal X-ray barium meal examination: it is an important method to diagnose this disease. 4.Fiber colonoscopy and biopsy histopathological examination: it has diagnostic value for lesions in the whole colon and uncinate ileum.