Bad breath that smells like feces is usually caused by gum disease, tonsil stones, or sinus infection, and rarely by a bowel obstruction. See a dentist or doctor.
Common causes
- Gum disease and bacteria on the tongue.
- Tonsil stones.
- Sinus infection or postnasal drip.
- GERD or stomach problems.
- Rarely, a bowel obstruction with vomiting.
What to do
Brush twice a day, clean your tongue, floss, and stay hydrated.
See a dentist
First. If dental causes are ruled out, see a doctor.
See a doctor urgently
If it comes with vomiting, severe belly pain or constipation.
Why breath can smell like feces
A fecal odor on the breath is rare and can be related to the mouth, nose, stomach or gut. Bad breath (halitosis) in most cases starts in the mouth, where bacteria produce volatile sulfur compounds such as hydrogen sulfide and methyl mercaptan.
Mouth and throat causes
- Gum disease and poor oral hygiene.
- Tonsil stones (tonsilloliths), calcified debris in the tonsils that smell strongly.
- Coating on the tongue.
- Dry mouth, as saliva normally cleans the mouth.
- Infections of the throat or sinuses, including post nasal drip.
Digestive causes
- Acid reflux and GERD.
- H. pylori infection.
- Gastroparesis.
- Bowel obstruction, which in rare and severe cases can cause fecal smelling vomit and breath. This comes with severe pain, bloating, vomiting and no passage of gas or stool and is an emergency.
Metabolic and other causes
Liver failure can cause a musty smell (fetor hepaticus), kidney failure a fishy or ammonia smell, and uncontrolled diabetes a fruity smell.
Hygiene steps
- Brush twice a day and clean the tongue.
- Floss daily.
- Drink water and chew sugar free gum.
- Gargle with saline.
- Replace your toothbrush every 3 months.
Dental checkups
Visit a dentist every 6 months or as advised, since most bad breath is dental.
See a doctor urgently if
Breath smells of stool with vomiting, severe belly pain, swelling and constipation.
See a doctor soon if
The smell lasts after good oral care for 2 weeks, or comes with a sore throat, reflux, weight loss or nasal discharge.
Possible origins of the odor
Breath that smells like feces is unusual and has several possible causes. The most common are mouth and throat problems: periodontal disease, tonsil stones, a coated tongue or untreated cavities, where bacteria release sulfur compounds. Sinus infections with postnasal drip and gastric reflux can add to the smell. Halitosis affects about 1 in 4 people in some degree, and over 85 percent of persistent bad breath comes from the mouth, according to dental research. Rarely, a bowel obstruction can cause fecal smelling vomit and breath, and this is a medical emergency.
What to do
Brush twice a day, floss, clean the tongue and stay hydrated. Dental check ups every 6 months find gum disease and decay. Over the counter mouthwash with cetylpyridinium chloride helps temporarily. See a dentist if the odor continues, and a doctor if it comes with abdominal swelling, vomiting, constipation, inability to pass gas or severe belly pain, since these point to obstruction. Also report fever, sore throat or a bad taste with nasal congestion, which may be due to infection.
Based on data from the American Dental Association and the Mayo Clinic
