Black stools after taking bismuth pectin, mainly because the bismuth contained in bismuth pectin will not be absorbed by the body. Pectin bismuth after taking black stools, mainly pectin bismuth containing bismuth will not be absorbed by the body, bismuth is darker in color, oral intake into the gastrointestinal tract so that the color of the stool becomes darker, there may also be a black tongue coating, belong to the normal reaction to the drug. Generally after taking bismuth pectin, the feces can be dark brown with no luster, and the feces color turns to normal within 1~2 days after stopping the medicine. Allergies and renal insufficiency are prohibited. In addition to black feces, nausea, constipation and other adverse reactions may occasionally occur. If black stools are still formed more than 3 days after stopping the drug, it is recommended to consult a doctor in time to exclude the possibility of gastrointestinal bleeding. The drug should be used under the guidance of a physician and in strict compliance with medical advice. Before using the drug, please read the instructions carefully to understand the precautions for use and the adverse reactions of the drug.