Feces Odor on Breath: What It Means and What You Can Do


Everyone experiences breath odor at some point in their lives. It can be concerning to have a strong odor on your breath that brushing and mouthwash don’t seem to help — especially if your breath smells like feces. While there are some benign causes for breath that smells like poop, most of the issues that cause this phenomenon are more serious and require medical attention.

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Possible causes

There are a number of different causes of breath that smells like poop, ranging from poor hygiene to liver failure. Let’s take a look at them.

Poor hygiene

Poor oral hygiene can cause your breath to smell like poop. Failing to brush and floss your teeth properly and regularly can make your breath smell because plaque and bacteria accumulate on and between your teeth. Food that’s not removed by flossing stays between your teeth, causing your breath to smell unpleasant.

Gum disease can also contribute to foul-smelling breath. It’s caused by neglecting oral hygiene. Neglecting your oral health also leads to an overgrowth of bad bacteria in the mouth, which can cause the odor on your breath. Dentures that aren’t properly cleaned on a daily basis can also cause severe halitosis.

Bowel obstruction

Intestinal obstructions are dangerous medical emergencies that occur when a blockage forms in either your large or small intestine.

A blockage in your intestinal tract can cause breath that smells like feces due not only to the feces that are trapped inside your intestines, but also due to food you’ve eaten that can’t move down your intestinal tract. Anything you eat while unable to pass a bowel movement remains inside the digestive tract and ferments, causing bad breath.

Besides unpleasant breath odor, someone with an intestinal obstruction may experience:

  • decreased appetite
  • severe bloating
  • abdominal swelling
  • constipation
  • nausea
  • vomiting
  • diarrhea
  • abdominal pain
  • severe abdominal cramps
  • inability to pass gas or stool


Prolonged vomiting — and the resulting dehydration — can cause bad breath due to dry mouth. Saliva cleans your mouth and reduces odor, but in cases of dehydration, you won’t produce enough saliva in extreme scenarios. Vomiting as a result of a bowel obstruction can cause your breath to smell like feces.

Sinus infections

Sinus and respiratory infections can cause your breath to smell like feces. These can be caused by bronchitis, viral colds, strep throat, and more. When bacteria move from your nose into your throat, it can cause your breath to have an incredibly unpleasant odor. Some other symptoms of sinus infections may include:

  • nasal drainage that is thick and yellow-green in color
  • a cold that lasts more than 10–14 days
  • low-grade fever
  • irritability and fatigue
  • postnasal drip that manifests as nausea, vomiting, cough, or sore throat
  • swollen eyes
  • headache

Children are more likely to develop sinus infections after a viral cold than adults, but similar symptoms can present in both.


Gastroesophageal reflux disease (GERD) can cause bad breath, including breath that smells like poop. This is because your stomach acid flows backward into the esophagus. This acidic backwash can irritate your esophageal lining, causing extreme discomfort. A person with GERD might experience:

  • mild reflux that occurs one to two times per week
  • moderate to severe reflux at least once a week
  • heartburn in your chest after eating, which could be worse at night
  • difficulty swallowing
  • regurgitation of sour liquid or food
  • the feeling of a lump in your throat
  • laryngitis
  • persistent cough
  • asthma that is new or worse than before
  • insomnia or inability to stay asleep
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