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.

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

Vomiting

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.

GERD

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

Ketoacidosis

Ketoacidosis is a severe complication in people who have diabetes. It occurs most often in people with type 1 diabetes, when the body produces a high level of acids in the blood called ketones. It’s a medical emergency that requires immediate attention, along with hospitalization.

Ketoacidosis could cause breath that smells like feces due the dry mouth or prolonged vomiting associated with the condition.

Symptoms of ketoacidosis include:

• extreme thirst
• frequent urination
• dry mouth and skin
• nausea or vomiting
• confusion
• abdominal pain
• high blood sugar levels
• high levels of ketones in the urine
• a flushed face
• fruity-smelling breath
• rapid breathing
• fatigue

Liver failure

Liver failure can be chronic or acute. Acute liver failure can happen suddenly and requires immediate medical attention. It can also cause the breath to smell like feces due to diarrhea and any resulting dehydration.

A person with liver failure might experience:

• weight loss
• jaundice
• diarrhea
• fatigue
• appetite loss
• nausea
• itching
• easy bruising or bleeding
• ascites (fluid buildup in the abdomen)
• edema (fluid buildup in the legs)

There are many ways to treat the conditions that cause breath with a fecal odor:

• Poor oral hygiene: If your bad breath is caused by plaque buildup due to poor oral hygiene, visiting the dentist for a cleaning could help. If you have gum disease, it’s important to treat it and get the inflammation in your mouth under control.
• Bowel obstruction: If you suspect you may have a bowel obstruction, seek immediate, emergency medical attention. Your doctor may prescribe bowel rest with IV fluids to treat a partial obstruction. For severe obstructions, surgery may be required. You might also be prescribed antibiotics, pain medication, or medication to reduce nausea.
• Vomiting: Treatment of vomiting depends on the causes. In most cases of viral infection and food poisoning, the symptoms must be allowed to pass. Sometimes severe vomiting requires anti-nausea medication or IV fluids in the case of dehydration.
• Sinus infections: Most sinus infections are treated with antibiotics prescribed by your doctor. Over-the-counter (OTC) pain medication may also be required to treat discomfort caused by the infection.
• GERD: GERD may be treated with OTC or prescription medications such as antacids(medications that lower acid production), proton pump inhibitors, or medications that help the lower esophageal sphincter stay closed. If you have GERD, you should avoid foods that aggravate your symptoms. In extreme cases, surgery may be necessary.
• Ketoacidosis: A person experiencing ketoacidosis will receive a combination of treatments in the hospital to normalize blood sugar and insulin levels. This includes insulin therapy, fluid replacement, and electrolyte replacement. You may receive antibiotics if your ketoacidosis was triggered by an infection or other illness.
• Liver failure: Your doctor may treat acute liver failure with medications that reverse the effects of poisoning or a liver transplant, if your condition is irreversible. For conditions like cirrhosis, which can lead to chronic liver failure, you may be treated for your dependence on alcohol, administered medication for hepatitis, advised to lose weight, or treated with other medications that control the causes and symptoms of cirrhosis.