There is gas in the anus that is blocked and cannot be discharged. Consider that it is related to hemorrhoids, intestinal obstruction, rectal prolapse, and rectal tumors. 1. Hemorrhoids: anal cushion displacement, varicose veins, etc. is the cause of hemorrhoids. Some patients may have no obvious symptoms, but some others have symptoms such as bleeding, perianal itching and pain. When hemorrhoids affect the anal sphincter contraction, can be manifested as anus have gas blocked discharge. 2. Intestinal obstruction: intestinal obstruction caused by anal gas blocking the discharge is mainly related to gastrointestinal dysfunction. Intestinal obstruction is related to intestinal adhesion, tumor, inflammatory bowel disease, etc. Patients are easy to be accompanied by paroxysmal abdominal cramps, loss of appetite, constipation, vomiting, inability to defecate or defecation, abdominal distension and other symptoms. 3. Rectal prolapse: the etiology is still unclear, may be related to sliding hernia, intussusception and so on. Typical symptoms of patients include rectal prolapse, urgency, mucus stool, anal sacrococcygeal distension, fecal incontinence and so on, and it can also be manifested as anus is blocked with gas and can not be discharged. 4. Rectal tumor: some patients can be affected by the tumor invading the intestine and affecting the function of anal sphincter, which can be manifested as the anus is blocked by gas and cannot be discharged. The cause of rectal tumor is still unclear, which may be related to heredity, improper diet, etc. The main manifestations include increased frequency of defecation, change of fecal character, abdominal pain, emaciation, and weakness. Patients who have gas in the anus and can’t get rid of it are advised to consult a doctor in time for examination, so as to avoid delaying the aggravation of the condition by following the doctor’s instructions after clarifying the disease.