Inflammatory bowel disease (IBD) is a chronic nonspecific inflammatory disease of the intestine, including ulcerative colitis (UC) and Crohn’s disease (CD). UC lesions involve only the colon (large intestine), while CD lesions can involve all parts of the gastrointestinal tract, with the terminal ileum and its adjacent colon predominant. Nowadays, the incidence of IBD is increasing, and an article about the key points of clinical knowledge of IBD was published in JAMA on May 21, briefly describing the knowledge about the main clinical manifestations, diagnosis and treatment of IBD, bringing medical inculcation and popularization for more IBD patients, and a systematic sorting for clinicians. The etiology of IBD is not yet clear, but there are four main factors that may play a role: genetic inheritance, environmental factors, intestinal flora, and abnormal immune response in the intestine. The age of the population diagnosed with IBD is mainly between 15-30 years old. Second, the main symptoms Clinical symptoms of IBD patients vary in severity, mainly manifesting as diarrhea, abdominal pain, bloody stools, fever, malaise and weight loss. As a result of systemic inflammatory involvement outside the gastrointestinal tract, patients with IBD may present with arthralgia or arthritis, visual or eye disorders, skin rashes, and liver disease. Symptoms usually show a smooth development of chronicity, but can also worsen suddenly and evolve into a fulminant form, which can lead to serious infection, bleeding or intestinal perforation, or even life-threatening if left untreated. Third, diagnostic points should be combined with the patient’s medical history, imaging examinations including CT, X-rays, and gastrointestinal endoscopy to evaluate the patient comprehensively. It should be emphasized that stool and blood tests should be used to exclude diarrhea caused by common infections. In contrast, abnormalities seen in routine blood tests include: anemia, elevated inflammatory markers, electrolyte disturbances (due to diarrhea), decreased albumin (due to inflammation and impaired nutrient absorption) and vitamin deficiencies (common in patients with CD, due to impaired nutrient absorption). Endoscopy is an essential diagnostic tool, including gastroscopy and colonoscopy, depending on the likely site of the patient’s lesion. The diagnosis is often confirmed by taking a tissue biopsy of the suspected site for pathological examination. The treatment plan for patients with IBD is graded, i.e., the treatment plan is determined according to the severity of the patient. For mild patients, anti-inflammatory treatment, oral or enema or suppositories can be used. In more severe cases, immunomodulators or immunosuppressants should be applied, which can be given orally, subcutaneously or by intravenous infusion. For patients with severe fulminant disease, hormones must be applied to suppress it. If conservative medical treatment is not effective, surgical treatment may be considered. In addition, it is important to note that patients with IBD who have lesions involving the colon are at a much higher risk of developing colon cancer, and therefore, long-term colonoscopic surveillance is necessary for these patients.