Bismuth Citrate Potassium Capsules should be taken before meals, not after, because Bismuth Citrate Potassium Capsules is a gastric mucosa protector, which can form a diffuse protective layer covering the ulcer surface in the acidic environment of the stomach, preventing the attack of gastric acid, enzymes and food on the ulcer, as well as reducing pepsin activity, increasing mucin secretion and promoting the release of prostaglandins from the mucosa, thus protecting the gastric mucosa. Bismuth Citrate Potassium Capsules are mainly used for chronic gastritis and to relieve stomach pain, heartburn, heartburn and acid reflux caused by excessive stomach acid, etc. During the medication period, there may be an ammonia taste in the mouth and the tongue and stool may be grayish black, which will disappear on its own after stopping the medication. If the symptoms are not relieved, please consult a doctor promptly.