Anal swelling and inability to pass stool may be caused by constipation, ulcerative colitis, rectal cancer, hemorrhoids and other diseases, which can be relieved by general treatment, medication and surgery. 1. Constipation: When patients have constipation, they may have the symptoms of not being able to pass stool and anal swelling, which can be helped by adjusting diet, drinking more water, eating more fruits or dietary fiber-rich foods. If the constipation is serious, under the guidance of the doctor to give keserol, lactulose and other drugs to help laxative, relieve anal swelling. 2. Ulcerative colitis: If you suffer from ulcerative colitis, under the stimulation of inflammation, you will be prone to anal swelling and not be able to discharge the stool. Under the guidance of the doctor can be improved by mesalazine, salazosulfapyridine tablets and other drugs. However, if the patient’s symptoms are more serious, surgical treatment should be considered, such as total colectomy, plus ileoanal pouch anastomosis and so on. 3. Rectal cancer: If the patient has rectal cancer, it will easily lead to the continuous exudation of the tumor and invasion to the surrounding tissues, and there will be anal swelling and inability to pass stool. Open surgery and laparoscopic surgery can be performed to improve the phenomenon of anal swelling and inability to pass stool. 4. Hemorrhoids: when suffering from hemorrhoids with thrombosis inflammation and edema, there will be a feeling of swelling in the anus, and when defecating, there will be blood in the stool, pain, or symptoms such as prolapse, partially accompanied by difficulty in defecation, and the phenomenon of not being able to defecate. It is necessary to give timely treatment such as hemorrhoidectomy or circumcision. If you have anal swelling and can’t pass stool, go to the hospital to improve the relevant examination, and give reasonable treatment for clear diagnosis.