Breath that smells like feces is usually caused by gum disease, tonsil stones, or a sinus infection, and rarely by a bowel obstruction. See a dentist or doctor.
Common causes
- Gum disease.
- Tonsil stones.
- Sinus infection.
- GERD.
- Rarely, bowel obstruction.
What to do
Brush twice daily, floss, scrape your tongue and drink water.
See a dentist
First. Then a doctor if the smell continues.
Urgent
Seek help if you have vomiting, belly pain and constipation.
Other causes beyond the mouth
Persistent fecal like breath odor is uncommon and deserves attention. Beyond dental plaque, bacteria on the tongue and tonsil stones, other sources include the digestive system and sinuses.
Tonsil stones
Tonsilloliths are hard clumps of debris, bacteria and mucus in the tonsil crypts. They smell strongly of sulfur and are found in up to 10% of adults, according to ENT studies. Gargle with salt water, and see an ENT if they recur.
Sinus and nose
Chronic sinus infections and post nasal drip let bacteria produce sulfur compounds. A nasal swab or imaging can help, and nasal rinses may reduce symptoms.
Digestive tract
- Gastroesophageal reflux.
- H. pylori infection, treated with antibiotics.
- Bowel obstruction or severe constipation, rarely causing fecal odor on the breath.
- Small intestinal bacterial overgrowth (SIBO).
Ketone breath
Low carbohydrate diets and fasting can produce acetone breath that smells fruity or like nail polish remover.
Diet and medications
Garlic, onions and some medicines release odorous compounds through the lungs. Smoking and alcohol dry the mouth.
Home check
Lick the back of your wrist and smell it after it dries, or floss and smell the floss, to get a sense of the odor.
Daily routine
Brush for 2 minutes twice a day, clean the tongue, floss, hydrate and see a dentist twice a year. Avoid alcohol based mouthwash that dries the mouth.
Urgent signs
Fecal smelling vomit, severe belly pain, swelling and inability to pass stool or gas require emergency care.
Tonsil stones and nasal sources
Tonsil stones (tonsilloliths) are small calcified clumps of debris, bacteria and dead cells in the tonsil crevices, and they release sulfur compounds that can smell foul. They affect an estimated 10 percent of people, more often those with large tonsils crypts. Chronic sinus infection with postnasal drip and a foreign object in the nose, especially in children, can cause a foul odor. Gargle with salt water, use a water flosser carefully, and see an ENT doctor if stones are frequent.
Digestive and metabolic clues
Gastroesophageal reflux, H. pylori infection and delayed stomach emptying can produce bad breath. Ketone breath, a fruity or nail polish smell, appears in diabetic ketoacidosis and needs urgent care. Kidney failure can cause an ammonia or fishy smell, and liver disease can cause a musty odor. A daily routine reduces volatile sulfur compounds: brush twice daily, floss, scrape the tongue, stay hydrated and use an alcohol free mouthwash with cetylpyridinium chloride or zinc. Dentists treat gum disease. If the smell persists despite good oral hygiene, see a doctor.
Based on data from the American Dental Association and the Mayo Clinic
