Why Does My Breath Smell Like Poop When I Floss?

Do you brush your teeth continuously and feel like it never freshens your breath? Are you a habitual or even obsessive flosser and yet, to your embarrassment, your breath still smells horrible?

While bottles of mouthwash may sit in your bathroom cabinet and you’ve cut out strong-smelling foods, it is quite possible for bad breath to still exist as a pervasive problem. Have you found yourself searching online for “When I floss it smells like poop”?

If this sounds like your struggle, you have come to the right place for answers. Nasty breath can be a difficult and embarrassing problem to figure out. It’s important that you are looking for solutions, though, because fecal-smelling breath can be an indication of something worse going on in your body.

Potential Causes and Treatment - What is the Problem?

Everyone struggles with smelly breath at one point or another. It’s merely a part of life and something that will happen from time to time, depending on medications, food, hydration, and so on. However, there is a marked difference between the occasional bad breath and consistently horrid odors. Routinely bad breath can certainly be a warning sign of something else going on in your body, and it merits further attention.

It is highly likely that you are already doing what you can to eliminate the odor, especially if it’s as unfortunate as smelling like feces. No one wants people feeling uncomfortable around them or even worse, pointing out your bad breath. When brushing, flossing, and mouthwash just can’t seem to make a difference, it’s time to more deeply examine the issue.

There could be a number of factors causing the feces smell on your breath, ranging from easily remedied situations to possibly more serious medical issues. Let’s discuss five of the most common causes.

1) Poor Oral Hygiene

Improper hygiene is probably the most common cause of terribly odorous breath. Even if you believe this doesn’t apply due to your frequent teeth brushing, other factors can lead to poor oral hygiene as well.

For instance, a chronic dry mouth can allow for extra bacteria growth due to the lack of saliva required to flush it away. Other factors to keep in mind could be infrequent professional dental cleanings, irritation or inflammation of the mouth, nose or throat (such as tonsil stones), oral infections, tobacco, or medications resulting in dry mouth.

Fecal-smelling breath originating from poor oral hygiene is the result of a buildup of bacteria. This build-up could be from plaque between your teeth, accumulation in your gums, food particles, and even gum disease. Improperly cleaned dentures may also result in this issue.


Have you heard of Gastroesophageal Reflux Disease? A doctor will typically diagnose GERD when a person has consistent acid reflux. This disease can result in fecal-smelling breath due to your stomach acid flowing back into your esophagus.


GERD is often accompanied by frequent heartburn ranging from moderate to severe in discomfort, as well as possible difficulty with swallowing, the feeling of a lump in your throat, laryngitis, and so on.

When acid backs up into the food pipe, those odors will be present on your breath. Bacteria can mix with the backed up food and acid, resulting in the fecal smell. If you think there is the possibility you may be dealing with GERD, it is important to seek medical help because the condition can cause further issues with your breathing, stomach, and teeth.

3) Abscessed Tooth

Another common root of fecal-smelling breath could be the presence of an abscessed tooth. An abscessed tooth is when a tooth becomes infected, even if it’s not painful yet. This infection is far greater than the typical tooth decay known as cavities. Rather, it’s when the pulp of the tooth itself becomes infected and is usually marked by severe pain.

Treatment normally involves either a root canal, endodontic surgery, or even a tooth abstraction. The odor of feces on your breath originates from the buildup of pus from the bacterial infection.

4) Sinus Infection

sinus infection

A sinus infection may begin feeling like a cold, but in actuality, it’s far different. These infections will last longer and cause more damage than a cold virus due to the bacteria continuing to populate within your tissues. Your sinuses are air-filled pockets and an infection results when they become filled with fluid and collected bacteria.

Bacteria can create extra discharge, pus, and a post nasal drip, all of which may result in your fecal-smelling breath. The additional mucus production results in more bacteria, which aggravates the infection, and in the end, your breath.

Occasionally, you may not even realize you have a sinus infection. It is highly possible for these infections to merely manifest as tooth pain, a singular post nasal drip, or headaches and a fever. Though the symptoms may not seem conclusive, when they are accompanied by feces-smelling breath, be sure to book a doctor’s appointment.

As for treatment, typically a doctor will prescribe a round of antibiotics if they suspect a bacterial infection rather than a bad viral cold.

5) Bowel Obstruction

abdominal pain

The final and most serious issue potentially causing feces-smelling breath would be a bowel obstruction. This occurs when either intestine is blocked and as a result, feces back up within the intestines, and recently eaten food is unable to move through the intestines. Due to the backed up food, the bacteria ferments and causes bad breath.

Bowel obstructions are extremely serious and should be treated with medical attention as soon as possible. Other symptoms of the blockage could be nausea, vomiting, inability to pass gas, abdominal pain and bloating, and a rapid heart rate.

The Bottom Line

Dealing with horrible breath odor is not only an annoyance, it can be an embarrassment. While typical bad breath may indeed be the result of strong-smelling food recently ingested, more serious conditions could be the cause of fecal-smelling breath and it's important to have the issue looked at by a medical professional.

It is certainly a good idea to evaluate the potential cause of this issue, whether it’s from poor oral hygiene, a sinus infection, an abscessed tooth, or potentially even GERD or a bowel obstruction. Not only can the right treatment possibly eliminate your odorous breath, but it could solve a bigger problem along the way.

In short, here are three ways to approach fecal-smelling breath:

  • Evaluate your body’s overall symptoms.
  • See a primary care physician.
  • See a dentist.

We hope this article was helpful for you, and please leave us a comment if you have any questions!

Looking for more? Check out 9 Enamel Erosion Causes - Infographic

Tialla Rising is a freelance writer living in the mountains of Arizona with her wonderful husband and their two fur-babies, a cat and a dog.  She has loved reading and writing for as long as she can remember, even self-publishing two novels as a teenager.  She loves going on adventures with her husband, though a cozy book, a stormy day, and a coffee also comprise her favorite moments.

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