Chronic colitis does not necessarily develop into colon cancer, ordinary chronic colitis, tuberculous colitis is generally non-cancerous, ulcerative colitis and other inflammatory bowel diseases may become cancerous, but there is no exact time, generally ranging from ten to several decades. 1. Ordinary chronic colitis: chronic colitis caused by bacterial or viral infection or poor diet may have symptoms such as abdominal pain, diarrhea, bloating, etc. It is generally non-cancerous, and the chances of its transformation into colon cancer are very low. 2. Tuberculosis chronic colitis: it is the inflammation of colon caused by tuberculosis infection, which can be manifested as abdominal pain, diarrhea, abdominal mass, low-grade fever and night sweating, etc. Generally, with active anti-tuberculosis treatment, it is almost non-cancerous. 3. Inflammatory bowel disease: such as ulcerative colitis, Crohn’s disease, especially ulcerative colitis, if repeated episodes, intestinal mucosa destruction, ulcer repair and proliferation, which can lead to cancer. There is no exact time for its cancerous transformation, generally ranging from ten to several decades. Generally, the longer the course of the disease, the increased risk of its cancer, to standardize the treatment, regular monitoring colonoscopy. It is recommended that patients with chronic colitis go to the hospital in time, standardize the treatment under the guidance of the doctor, and regularly review the colonoscopy.