Bad breath combined with farting is a priority for digestive problems, and gastrointestinal disorders are also a common cause of bad breath. H. pylori infection is an important cause of gastrointestinal disease and bad breath, which can be accompanied by abnormal diet and stool; acute and chronic gastritis, peptic ulcers also often make the mouth smell sour; pyloric obstruction and advanced gastric cancer often smell like rotten duck eggs; it is recommended to visit the hospital’s gastroenterology department for tests such as a carbon 13 breath test or gastroscopy to determine the cause.