The first is that if a woman has had ulcerative colitis, sometimes the rupture of the blood vessels of the intestinal mucosa can lead to blood in the stool, and colonoscopy can make a clear diagnosis. The second is that if a woman has an anal fistula, sometimes the fistula does not heal for a long time will also lead to infection at the internal mouth, so there will be some mucus pus blood stool from the anus out. The third, if the patient has previous hemorrhoids, especially internal hemorrhoids, in the diet a lot of stimulating food, such as chili, will cause the nucleus of the hemorrhoid stagnation, swelling, which leads to the rupture of the hemorrhoid veins and cause blood in the stool. If the color of blood in the stool is dark red, the bleeding site is far from the anus, if it is bright red, it is considered closer to the anus, and rectal diagnosis should be performed, and if necessary, colonoscopy can be performed to clarify the diagnosis.