Bleeding in the stool of pregnant women may be caused by hemorrhoids, anal fissure, rectal polyps, gastroduodenal ulcers and other reasons. 1. Hemorrhoids: due to the increasing uterus pressure on blood vessels during pregnancy, venous return obstruction may cause hemorrhoids or aggravate the existing hemorrhoids, leading to bleeding in the stool of pregnant women. 2. Anal fissure: due to the pressure of the uterus during pregnancy, intestinal peristalsis is weakened, easily causing constipation. When the stool is relatively dry, it may cause tearing of the soft tissues of the anus, leading to bleeding in the stool of pregnant women. 2. Rectal polyps: due to the presence of rectal polyps in pregnant women, if long-term bowel difficulties, abdominal pressure will increase. This causes the blood vessels on the mucosal surface of the polyp to rupture, which can lead to symptoms of bleeding in the stool in pregnant women. 3. Gastroduodenal ulcer: If a pregnant woman has a gastroduodenal ulcer, it may also lead to bleeding in the stool, and the color of the blood is usually black. Clinically, pregnant women with bleeding in the stool should actively go to the hospital, under the guidance of the doctor standardized treatment.