Bismuth Magnesium Granules for Stomach may cause side effects such as constipation, diarrhea, and black stools. After stopping the drug can generally disappear on their own, can also be life conditioning and medication such as lactulose, montelukast and so on. 1. constipation: gastric bismuth magnesium particles is bismuth aluminate, magnesium bicarbonate, sodium bicarbonate and other drugs composed of composite preparations, due to the reduction of gastric acid may lead to indigestion and constipation symptoms, you can eat bananas, dragon fruit, celery, spinach and other vegetables and fruits with high content of fiber, you can also take lactulose and other drugs. 2. Diarrhea: stomach bismuth magnesium particles due to affect the digestive function may also lead to diarrhea, you can reduce the amount of medication, you can also take montelukast and other drugs to protect the intestinal mucosa treatment. 3. Black stool: bismuth aluminum magnesium particles in the stomach bismuth magnesium particles is a black substance, due to the intestinal tract is not absorbed in the intestinal tract and the substances in the intestinal tract dyed black and the symptoms of black stools, generally can be recovered after discontinuing the medication, no need for special treatment. If you take bismuth magnesium gastric granules side effects, you can take medication under the guidance of a doctor to treat or stop taking medication, do not recommend self-medication.