Frequent constipation results in the contents of the stomach and intestines not being effectively digested and absorbed, so patients may experience symptoms of bad breath. Frequently constipated patients, the gastrointestinal tract accumulates a large amount of content, and the content is not excreted for a long time, resulting in the decomposition of bacteria and content, a large number of odorous gases accumulate in the digestive system, which is prone to cause halitosis. And often constipated patients gastrointestinal peristalsis slower, will also exacerbate the gastrointestinal contents of the savings, decomposition, aggravate the occurrence of bad breath. Generally often constipated patients with poor dietary habits, such patients eat more meat-containing foods, such foods will also increase the patient’s bad breath. And patients often constipation is easy to cause emotional instability, endocrine disorders, these will cause bad breath.