1.Persistent and more severe constipation since early childhood, even without any obvious feeling of bowel movement. 2.Sudden onset of constipation when constipation has never occurred before. 3.Constipation was already easy to constipate, and it is especially serious recently. 4.Stubborn constipation has been difficult to improve. Yao Haidong, Department of Anorectal Medicine, Daqing Longnan Hospital 5.Feces with blood or mucus, especially when the blood color is not fresh. 6.Deformed stool with grooves or signs of pressure. 7, accompanied by strong abdominal pain or vomiting. 8.Extraordinarily long duration of stool.