What stomach problems cause bad breath? Related conditions and treatments

Medically reviewed by Leslie Greenberg, MD
Board-Certified Family Physician
Updated Jun 10, 2024  •  Published Jan 11, 2024
Fact Checked
In this article:

Most people think of bad breath (halitosis) as a mouth problem. Avoiding certain foods, brushing, flossing, mouthwash, and regular dental visits are often the best ways to control halitosis. However, the mouth is only one part of the digestive tract that extends from the back of the throat to the rectum. Any number of problems in that digestive tract could cause bad breath: problems in the esophagus, the stomach, and even the intestines can all cause bad breath. If that’s the case, good oral hygiene, mouthwash, and breath fresheners do little to help the breath. The esophagus and the stomach are the most likely of all the places where problems can arise that cause bad breath. As far as the stomach is concerned, only a few problems cause bad breath. The most common are gastroesophageal reflux disease (GERD) and a Helicobacter pylori (H.pylori) infection of the stomach lining. These are very different conditions, but they have one thing in common: they hurt. The signature symptoms of GERD are heartburn and pain behind the breastbone, along with other symptoms such as bad breath. An H. pylori infection is often symptomless, but when the infection compromises the stomach lining or causes a stomach ulcer, the signature symptom is stomach pain, especially right after eating.

Key takeaways:

  • Stomach problems causing bad breath are common and may be caused by GERD, H. pylori infection, slow emptying of the stomach, and the narrowing or blockage of the outlet between the stomach and the small intestine. Intestinal problems may cause persistent vomiting, which will also cause bad breath.

  • Typically, stomach problems causing bad breath do not require immediate medical attention.

  • Stomach problems causing bad breath generally require treatment because of other symptoms and possible complications. Depending on the condition, they typically resolve with treatment within a variable time frame.

  • Treatment of stomach problems causing bad breath may include dietary changes, lifestyle changes, antacids, stomach acid reducers, antibiotics, drugs that speed up stomach emptying, anti-nausea drugs, or surgery. 

  • Depending on the condition, stomach problems causing bad breath can be managed with dietary and lifestyle changes.

  • Use coupons for stomach problems causing bad breath treatments, like Prilosec, Tagamet, amoxicillin, clarithromycin, metronidazole, and Reglan, to save up to 80%.

What causes stomach problems that cause bad breath?

Bad breath due to stomach problems is either the result of

  • Regurgitation, because stomach contents smell bad

  • Bacterial infection of the stomach, because some bacteria give off smelly gasses,

  • Stomach contents getting stuck in the stomach

The most common causes of persistent regurgitation or vomiting are:

  • GERD

  • Bacterial infections of the small intestine

  • Small intestinal bacterial overgrowth (SIBO)

The one bacterial infection of the stomach that frequently causes bad breath is H. pylori. These bacteria excrete sulfur compounds as a waste product, making the breath smell like rotten eggs.

The most common causes of stomach contents getting stuck in the stomach include:

  • Delayed stomach emptying (gastroparesis)

  • Narrowing or obstruction of the pyloric valve (pyloric stenosis), which is more common in newborns and infants but only very rarely occurs in adults

Similarly, intestinal problems can also get food stuck in the intestines, allowing bacteria to thrive and produce gasses full of foul-smelling sulfur compounds that can pass through the stomach and out the mouth. These are not stomach problems but might be mistaken for them because of symptoms like abdominal pain or bloating. These conditions include:

Should I be worried about stomach problems that cause bad breath?

Bad breath that is persistent and pronounced should be evaluated by a doctor, dentist, or other healthcare professional. The most common cause of bad breath is poor oral hygiene and its consequences: gum disease and tooth problems. It could also be a sign of a structural problem with the esophagus. Though not very common, some people have pockets or structural anomalies that allow undigested food particles to get stuck in the esophagus. These food particles then rot and emit bad odors. These are all conditions that require the attention of a healthcare provider.

If it’s a stomach problem, then worrying about it will depend on other symptoms. Talk to a healthcare provider if there are symptoms like repeated vomiting, pain, diarrhea, blood in the vomit, or weight loss. Severe vomiting requires immediate medical care. Some of the complications of the causes of stomach problems that cause bad breath include:

  • Bleeding

  • Inflammation, tears, or sores in the esophagus

  • Abdominal swelling (peritonitis)

  • Stomach cancer

  • Esophageal cancer

  • Malnourishment

  • Weight loss

  • Intestinal failure

How are the causes of stomach problems that cause bad breath diagnosed?

Diagnosis will depend on other symptoms. If the only symptom is halitosis, diagnosis may need to start with a dental exam. If there are other symptoms, including gastrointestinal symptoms, people should start by seeing a primary care provider or similar healthcare professional. The initial diagnosis may be based on a medical history, the symptoms, and a physical exam. Sometimes, the doctor will refer the person to a specialist in digestive system disorders called a gastroenterologist.

A gastroenterologist, doctor, or other healthcare professional may employ one or more tests to diagnose the underlying cause definitively. The clinician will choose tests based on the suspected cause. These include:

  • A breath test to detect H. pylori infection or SIBO

  • Stool tests

  • Blood tests

  • An upper endoscopy to examine the stomach lining with a camera attached to a long thin tube

  • A biopsy (microscopic examination) of a sample taken from the stomach lining during the endoscopy (H. pylori)

  • A gastric emptying study to measure the speed at which food enters and then leaves the stomach

  • CT or MRI scans to reveal obstructions

Are stomach problems that cause bad breath contagious?

Of the causes of stomach problems that cause bad breath, only H. pylori infections are transmissible. Infections are spread through the feces. However, most people are already colonized with H. pylori, often at a very young age. The spread of bacteria and viruses that live in the gastrointestinal tract can be prevented by regular handwashing and proper food preparation.

How long do stomach problems that cause bad breath last?

Several stomach disorders can cause bad breath. Some are completely curable, but others can only be managed:

  • GERD is a chronic condition, but the acid reflux episodes can be reduced in frequency by avoidance of triggers and by taking medications

  • For most individuals, H. pylori infection can typically be cured in about two weeks, but there is always a risk of reinfection. According to research, resolving an H. pylori infection can alleviate the issue of bad breath.

  • Gastroparesis is difficult to reverse and may be a chronic condition that requires prescription medications

  • Intestinal problems like IBS, Crohn’s disease, and celiac disease are usually chronic conditions that can be managed, but infections and bacterial overgrowth can be treated with a short course of antibiotics

How to stop stomach problems causing bad breath

Treatments will be based on the underlying medical condition, ranging from lifestyle changes to surgical interventions. 

GERD is usually treated by dietary changes, lifestyle changes, and medications that reduce the stomach’s acid production, such as proton pump inhibitors and H2 blockers. Antacids might also help. Severe cases may require medications that speed up stomach emptying called prokinetics or motility agents.

H. pylori infection is usually treated only if it is causing other problems like gastritis or peptic ulcers. Treatment is imperative if peptic ulcers recur, a medical condition called peptic ulcer disease. Treatment will primarily consist of a limited course of antibiotics, proton pump inhibitors, and sometimes bismuth subsalicylate. 

Delayed stomach emptying (gastroparesis) is primarily treated with medications that speed up stomach emptying (motility agents) and symptom relief drugs like anti-nausea medications. 

While uncommon, surgery is typically necessary for the majority of pyloric stenosis cases.

Small intestinal bacterial overgrowth (SIBO) is treated with antibiotics and dietary supplements if the person is malnourished because of malabsorption problems.

Living with stomach problems that cause bad breath

Bad breath is a problem, but poor gut health is even worse. The best way to prevent bad breath due to stomach problems—or any other digestive system issue—is to take good care of the stomach and digestive system. Keeping the gastrointestinal tract in good shape involves:

  • Eating a healthy diet

  • Eating a high-fiber diet

  • Consuming foods that contain probiotics

  • Avoiding triggers that cause problems like acid reflux, nausea, vomiting, pain, and excessive belching

  • Eating mindfully and slowly

  • Exercising

  • Washing and preparing foods carefully

  • Washing your hands before eating

  • Making sure drinking water and cooked food are sanitary

  • Managing stress and practicing relaxation techniques

RELATED: 9 ways to improve your gut health

Most importantly, get medical advice about bad breath

Bad breath is sometimes a sign of a medical condition that can or should be treated. Some people indeed have bad breath because they neglect their oral health. The fix is simple: brush, floss, and see a dentist regularly. Some people have bad breath for minor reasons such as dry mouth. The problem may not be curable in these cases, but it is fixable. Some people have bad breath for more serious reasons like gum disease, GERD, H. pylori, or bacterial infections. No matter the cause, a healthcare provider, a dentist, a primary care provider, a gastroenterologist, or other healthcare professionals are needed. They will know what to do and can give you medical advice on what you can do to eliminate bad breath.

What’s next? Additional resources for people with stomach problems that cause bad breath

Test and diagnostics

Treatments

Scientific studies and clinical trials

Medically reviewed by Leslie Greenberg, MD
Board-Certified Family Physician

Leslie Greenberg, MD, is a board-certified practicing family physician with more than 25 years of doctoring experience. She was a psychology major at Northwestern University near Chicago, then graduated with an MD from the University of Nevada School of Medicine. She completed her family medicine residency at St. Joseph Hospital in Wichita, Kansas. She has trained more than 350 family medicine resident-physicians, been in private practice, and delivered babies for 22 years.

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