Most anal strictures are caused by inflammation, surgical complications and tumours. If left untreated, the stricture will gradually worsen, making defecation more and more strenuous and aggravating the inflammation and fibrosis in the anus, creating a vicious circle; while anal strictures caused by tumours may develop distant metastases if the tumour is not removed in time, endangering the patient’s life. This is why it is important to seek prompt medical attention, actively search for the cause and receive regular treatment for anal stenosis.