There are many reasons for a month of blood in the stool. If the color of blood in the stool is dark red, it may be upper gastrointestinal bleeding, such as gastric ulcer, duodenal ulcer, small intestine diverticulum, small intestine polyp can cause blood in the stool, and blood in the stool is usually dark red. If the color of blood in the stool is bright red, it may be lower gastrointestinal bleeding, the bleeding site is closer to the anus, common are mixed hemorrhoids, especially internal hemorrhoids caused by bleeding, rectal polyps and rectal adenomas can cause bleeding, sometimes intestinal malignant tumors also cause blood in the stool. The reason for the blood in the stool is many, so you should actively go to the anorectal department, perform rectal examination, and if necessary, place a therapeutic anoscope or colonoscope to clarify the cause and location of the bleeding, and then treat the symptoms.