Bitter mouth is not a manifestation of stomach cancer in early stage. Early stage of stomach cancer may not have obvious uncomfortable symptoms, although some stomach tumor patients may have bitter mouth in early stage, but like exuberant liver fire, gastritis, cholecystitis and bad dietary habits can also cause bitter mouth, so you can’t rely on the bitter mouth to determine whether it’s the early stage of stomach cancer or not. Most of the time, bitter mouth is caused by indigestion, which is caused by improper eating, drinking alcohol for a long time or overeating; bitter mouth is also caused by strong liver fire and consuming spicy and greasy food for a long time; bitter mouth is also caused by excessive secretion of stomach acid or bile due to gastritis or cholecystitis; and bitter mouth is also caused by staying up all night for a long time, being anxious, nervous, and being angry. If the symptoms of bitter mouth are not relieved, or accompanied by other symptoms, you should go to the regular hospital in a timely manner to consult a doctor to identify the cause of the problem and then give targeted treatment.