Constipation and diarrhea are both manifestations of intestinal dysfunction, and the main causes include irritable bowel syndrome, non-specific ulcerative colitis, Crohn’s disease, intestinal tuberculosis, intestinal parasitic diseases, intestinal tumors, etc. If constipation and diarrhea occur alternately, we should pay attention to them. If irritable bowel syndrome is caused, usually there is spicy food or cold food before the onset of the disease, oral medication to regulate intestinal flora can be restored; however, if there is no obvious cause before the onset of the disease, or if it occurs frequently, we need to actively exclude malignant diseases, and pay attention to abdominal physical examination, observe whether there is pressure pain, masses, etc., and improve colonoscopy and routine stool examination if necessary To clarify the cause of the disease. Once symptoms such as vomiting and abdominal pain appear, it is necessary to be alert to the occurrence of intestinal obstruction and intestinal perforation. In addition to malignant intestinal diseases, non-specific ulcerative colitis, Crohn’s disease and other intestinal inflammatory diseases can repeatedly stimulate the intestinal mucosa and appear inflammatory masses, which generally have a long course and patients with systemic wasting symptoms are not heavy. In the case of intestinal tuberculosis or intestinal parasitic disease, the course of the disease is generally intermediate between tumor and inflammatory disease, with systemic wasting symptoms, but not heavy, and intestinal parasites can migrate to the lungs, brain, etc. Therefore, once there is constipation and diarrhea alternately should not be careless, if necessary, need to perform colonoscopy, stool routine examination to further clarify the cause, according to the cause of symptomatic treatment.