A 4 mm colon polyp is usually not serious. Colon polyps are classified into neoplastic and non-neoplastic lesions. Neoplastic lesions are primarily adenomatous polyps. This includes papillary adenomatous polyps, which often refer to inflammatory polyps and are non-neoplastic lesions. However, colon polyps are currently relatively small, 4 millimeters, the condition is not very serious, and the rate of malignant transformation is very low. Generally do not cause obvious clinical symptoms, but may also lead to the phenomenon of fresh blood after stool. Although the colon polyp is a benign disease, but there is a certain chance of malignant changes, in order to avoid malignant changes, should be taken as early as possible to take surgical treatment, can be removed under the colonoscopy surgery, and after the operation to do pathological examination. Although 4mm colon polyps are not serious, they should be reviewed regularly for colonoscopy. If symptoms occur, they should be treated accordingly.