Oral amoxicillin diarrhea belongs to the adverse reaction caused by the drug, which is bad. Amoxicillin belongs to the semi-synthetic penicillin antibiotics, clinically used in the treatment of infectious diseases of the respiratory tract, genitourinary tract, skin and soft tissues. Common adverse reactions include nausea and vomiting, diarrhea, rash, asthma, anemia, anxiety, and insomnia. Since taking antibiotics alters the normal flora of the intestinal tract, almost all antibiotics cause an overgrowth of Clostridium difficile, which can lead to associated diarrhea, which may present as a mild symptom, but can also progress to fatal enteritis. Therefore, if diarrhea persists or symptoms are severe and intolerable, prompt medical attention is required for symptomatic treatment or change of anti-infective drugs. Amoxicillin should be used under medical supervision to avoid adverse effects.