Symptoms of inflammatory bowel disease are common: 1. Ulcerative colitis: the onset in the colon, with pus and blood stools, fever, anemia and other symptoms, the disease can be diagnosed by colonoscopy; 2. Crohn’s disease: the symptoms are atypical, some patients have a history of abdominal pain for many years, or symptoms such as constipation and diarrhea, which cannot be diagnosed solely by colonoscopy, and the diagnosis is easily missed in clinical practice. Crohn’s disease is more complex, mainly develops in the small intestine, at the end of the ileum. Although Crohn’s disease can occur in the entire gastrointestinal tract from the mouth to the anus, the onset is mainly in the end of the ileum, and general colonoscopy or gastroscopy cannot detect the lesion, plus the symptoms are atypical, so it is often easy to miss the diagnosis.