Taking quadruple medication (eradication of Helicobacter pylori treatment) usually does not cause blood in stool. Blood in stool should be considered whether it is related to hemorrhoids, anal fissure or rectal cancer. 1. Hemorrhoids: when internal hemorrhoids appear, the main manifestation is bleeding after stool, intermittent bleeding after stool can be seen, or there is bleeding during stool, dripping blood or blood on the handkerchief. 2. Anal fissure: in the process of treatment, if there is constipation, dry stools appear, force defecation can lead to mechanical damage to the perianal mucosa, there is severe pain during defecation, you can see fresh blood on the feces or there is dripping blood. 3. Rectal cancer: after the onset of the disease, when defecating, it can cause the cancer to break and bleed, and see blood, mucus or pus and blood in stool. It is suggested that after taking Quadruple Therapy, if there is blood in stool, consult doctor in time, and after clear diagnosis, then carry out symptomatic treatment for the right cause.