Sour mouth and bitter mouth may be reflux esophagitis, indigestion, cholestasis, dry syndrome and other reasons, you can take omeprazole, domperidone and other drugs to treat. 1. Reflux esophagitis: The reflux of gastric acid and other stomach contents into the mouth is caused by factors such as dysfunction of the lower esophageal sphincter and reduced barrier function of the esophageal mucosa, which leads to acidity and bitterness in the mouth. You can take omeprazole, epprazole, aluminum sulfate, bismuth pectin and other drugs to treat it. 2. Indigestion: unhealthy eating habits, mental and psychological disorders, poor sleep and other factors lead to gastrointestinal peristaltic disorders, indigestion and food stagnation, so the mouth will be sour and bitter. You can take gastrointestinal tablets, domperidone, mosapride, compound digestive enzymes and other medications. 3. Bile stasis: cholecystitis, gallstones, bile duct stones and other factors lead to bile stasis, so it will be sour mouth and bitter. You can take ursodeoxycholic acid, adenosylmethionine and other drugs to treat it. 4. Dry syndrome: the autoimmune system produces antibodies against the salivary glands, lacrimal glands and other self glands, leading to reduced secretion of saliva and so on, so it will be sour mouth and bitter. Prednisone, tacrolimus, hydroxychloroquine, methotrexate and other medications can be taken. Patients with symptoms of sour mouth and bitter mouth, it is recommended to consult a doctor in a timely manner, improve the relevant examination to clarify the cause of the disease, and pay attention to the use of medication under the guidance of the physician.