Compound Calamus Alkaline Bismuth Nitrate Tablets is an antacid astringent western medicine, which can be used for the treatment of gastric and duodenal ulcers and gastritis and other diseases. Compound Calamus Basic Bismuth Nitrate Tablets is a compound preparation, whose components include basic bismuth nitrate, magnesium bicarbonate, sodium bicarbonate, calamus root powder and so on. Bismuth nitrate can protect gastric mucosa, astringent, antidiarrheal; magnesium bicarbonate and sodium bicarbonate can neutralize gastric acid, reduce the ability of pepsin to decompose gastric wall proteins, and weaken or lift the corrosive and stimulating effect of gastric acid on gastrointestinal ulcer surface; magnesium ions have a diarrheal effect; rhubarb and calamus can eliminate constipation and enhance the digestive function of gastrointestinal tract. Clinically, it is mainly used in the treatment of gastric and duodenal ulcers and gastritis. Its adverse reactions are not clear, during the period of taking the drug, the dark color of the stool is a normal phenomenon. In addition, pregnant women and those who are allergic to the ingredients contained in this product should be prohibited, and it is best not to use it when there are acute gastric mucosal lesions, and it is not advisable to take it for a long time in large doses. The drug is a prescription drug, the specific use should also be under the guidance of a physician to strictly comply with medical advice.