Probiotics can be taken when there is blood on the surface of stool. Probiotics can mainly play the role of regulating the disorder of intestinal flora, and there is almost no adverse reaction. Therefore, patients may try to take probiotics when there is blood on the surface of stool, and then judge the effect of treatment. If the rectal mucosa bleeds and the anal canal mucosa bleeds a little due to constipation, taking probiotics can improve the symptoms of constipation and thus can relieve the bleeding caused by constipation. In addition, if the bleeding of anal fissure occurs during defecation due to constipation, eating probiotics can also improve the symptoms of constipation and reduce the occurrence of anal fissure. Of course, patients with blood in the stool also need to be alert to the presence of bleeding caused by intestinal lesions, such as intestinal polyposis or intestinal tumors, so it is recommended that patients go to the hospital if necessary.