Bad breath caused by poor gastrointestinal function. It can be regulated by daily diet and physical exercise. If the bad breath is caused by poor gastrointestinal function, you can take some drugs, such as domperidone and other drugs. It can increase gastrointestinal peristalsis, promote gastrointestinal emptying to shorten the time of food retention in the gastrointestinal tract, and pay attention to strengthening nutrition to eat more food containing fiber, such as bananas, celery, spinach, etc.. Eat a small amount of non-greasy food, eat less indigestible food, and pay attention to increase exercise to promote gastrointestinal peristalsis. If the gastrointestinal function is weakened due to chronic gastritis and other diseases. It is recommended to go to the hospital for examination and further treatment. You can also use Chinese medicine to treat halitosis. According to Chinese medicine, halitosis is caused by spleen deficiency and dampness and heat, and the clear qi cannot rise and the turbid qi cannot fall, so it is difficult to cure it with general medication. You can choose to use the traditional Chinese medicine black alum, black dates, walnuts, gardenia and other treatment, can be quickly cured. In short, there are many kinds of treatment programs for bad breath caused by poor intestines and stomach, you can choose the right treatment program according to the different physical conditions of individuals.