Bad breath caused by gastrointestinal problems is recommended to take drugs to promote gastrointestinal peristalsis (such as domperidone, etc.), to promote digestion (lactobacillus tablets, etc.) or gastric acid inhibiting drugs (such as rabeprazole, etc.) under the guidance of a doctor. 1. If there is dyspepsia, resulting in food not being fully digested and absorbed and fermented to produce bad breath, you can take prokinetic drugs such as mosapride or domperidone, etc., which can promote gastrointestinal peristalsis in order to utilize the digestion and absorption of food. 2. Bad stomach and intestines can also take drugs to promote digestion, such as lactobacillus tablets, gastrointestinal tablets, etc.; in order to promote the full digestion and absorption of food. 3. Excessive stomach acid leads to acidic belching will also appear the symptoms of bad breath, you can take omeprazole or rabeprazole and so on to inhibit the secretion of gastric acid. In addition, we must do a good job of oral care, maintain good oral hygiene to prevent the aggravation of bad breath symptoms. Patients should go to the hospital in a timely manner, under the guidance of the doctor, complete the relevant examinations, to determine the cause of the disease, to be systematic and regular treatment.