This is an important questions to discuss with your dentist
, especially if you are not consuming high-sulfur foods and if you consistently practice good dental hygiene. I recommend that you see a dentist to find out whether an underlying oral condition may be causing it. Persistent bad breath or bad taste in the mouth may be warning signs of gum (periodontal) disease. Yeast infections of the mouth and dental caries should also be checked out for causing bad breath. If your dentist gives you clean bill for your oral health and the foul odor is not of oral origin, I suggest an appointment with a primary care doctor
or a specialist to be evaluated for underlying reason for the potential stomach problem or any other condition. Your esophagus is closed, but if you have a reflux serious enough to be bringing up stomach contents between the stomach and the esophagus, it is an indication of gastroesophageal reflux disease or GERD. Another medical condition dry mouth can also cause bad breath. Dry mouth is a common cause of the "morning breath" when saliva production nearly stops during sleep, which allows bacteria to grow. Another cause of bad breath might be tonsil stones where food particles, bacteria and dead cells are trapped in, so it may be time to check them out. There are many other possible sources of bad breath to name. Please see your doctor soon to get the root of it so you can cure your problem.