You do not have dental caries. You brush your teeth regularly. You even use mouthwash after brushing. You don’t forget to floss. But still your breath smells foul.

If you have a persistent bad breath and you know you have stellar oral hygiene practices, there’s a huge possibility that the smell is coming from deep within you, in particular your digestive system.

According to doctors, there are a number of problems concerning the gastrointestinal (GI) tract that can cause bad breath that won’t go away no matter what you do.

Sure it can be a very embarrassing matter to discuss with your doctor, but it’s only your doctor who can help identify what digestive problem can be blamed for that persistent bad breath.

Here are some of the most common GI tract-related issues that can cause bad breath:

Acid Reflux

Simply put, acid reflux is caused by stomach acid that comes back up your esophagus, something that it’s not supposed to do. At times food in the stomach may also escape together with acid.

Heartburn, difficulty with or excessive burping, a sour taste in the mouth, chronic sore throat, discomfort when swallowing — these are the usual symptoms of acid reflux. Oh, and it can cause bad breath, too.

It’s important for acid reflux to be controlled with dietary and lifestyle changes, and at times with medications. Otherwise, it may lead to a bigger problem which is the one discussed next.


Short for gastroesophageal reflux disease, GERD is a more severe form of acid reflux. Needless to say, it tends to attack more frequently, and the symptoms it brings are usually more intense.

Having GERD treated right away is of utmost importance as it can lead to some very serious complications. For instance, experts say that it can increase a person’s risk of having cancer of the esophagus.

Just like acid reflux, GERD can be managed by doing some changes with the diet as well as lifestyle. Commonly, medications that reduce the production of stomach acid are prescribed.


We all know that constipation is something that can cause straining during bowel movements, abdominal pain and cramping, and also bloating. Did you know that it can also cause your breath to reek?

If you have constipation, fecal matter gets trapped in your colon for days or even weeks. According to experts, the odor they give off can actually escape your body by means of your mouth!

Fortunately, constipation can be easily remedied by consuming fiber-rich foods, drinking plenty of water and having more exercise. See a doctor if your constipation doesn’t seem to want to go away.


Are you aware that stomach or duodenal ulcers are due to the presence of a bacterial pathogen called helicobacter pylori or H. pylori? And did you know that the said type of microbe can cause bad breath, too?

In fact, one of the tests for the presence of H. pylori is by means of the breath — samples of your breath will be collected and analyzed at the laboratory.

Other than bad breath, having stomach ulcers due to H, pylori can cause abdominal pain, nausea, loss of appetite, weight loss, excessive burping and bloating. However, at times there are no symptoms.


Short for irritable bowel syndrome, IBS is a very common disorder of the digestive system that affects the large intestines. Often, you have to deal with IBS for life if you are diagnosed with it.

The foods you consume are some of the biggest triggers for IBS. Some of those that are known to cause IBS to strike include high-fiber foods, greasy foods and carbonated beverages. Having large meals is a culprit, too.

Doctors say that one of the symptoms of IBS is bad breath. Others include abdominal bloating and cramping, heartburn, weight loss, and the presence of mucus in the stool.