Defecation is black has no relationship with taking amoxicillin more, it may be due to drug factors, food factors, digestive bleeding and so on. Amoxicillin commonly used dosage form of tablets, capsules, etc., different dosage form indications, adverse reactions and contraindications are the same, can be used for the treatment of otitis media caused by sensitive bacteria, urinary tract infections, etc., but also can be used in conjunction with other medications to eradicate Helicobacter pylori. When using the drug, there may be diarrhea, nausea and other adverse reactions, penicillin allergy, etc. is prohibited, but there is no information that taking amoxicillin will cause obvious black stools. 1. Drug factors: if you take too much iron supplements (such as ferrous sulfate, etc.), bismuth (such as bismuth potassium citrate, colloidal bismuth, etc.) and other drugs, can also cause black stools. 2. Food factors: If you eat too much pig blood, sheep blood and other foods rich in iron, iron can be combined with sulfide in the intestinal tract to form iron sulfide, resulting in black stools. 3. Gastrointestinal bleeding: If peptic ulcer, acute gastric mucosal lesions, NSAIDs drugs and other drugs can cause gastrointestinal bleeding, there may be pain in the middle and upper abdomen, vomiting blood, black stools and other phenomena. In addition, malignant tumors of the intestines such as colon cancer, blood system diseases such as leukemia can cause black stools, etc. It is recommended that patients go to the hospital in time to exclude physiological factors, and then receive treatment as soon as possible.