Sweet-Smelling Feces: Causes, Concerns, and When to See a Doctor
Key points
- Watery diarrhea (at least three bowel movements per day for two or more days)
- Fever
- Stomach tenderness or cramping
- Loss of appetite
- Nausea
While not a common topic of conversation, changes in the odor of your stool can be an important indicator of your digestive health. If you've noticed an unusual, sweet smell, it's natural to have questions. While often temporary and related to your diet, this distinct odor can sometimes signal an underlying medical condition that requires attention.
This article provides a comprehensive overview of the potential causes of sweet-smelling feces, clarifies common misconceptions, and outlines when it's time to consult a healthcare professional.
The Primary Medical Cause: Clostridioides difficile (C. diff) Infection
One of the most well-documented medical reasons for a "sickeningly sweet" stool odor is an infection with the bacterium Clostridioides difficile, commonly known as C. diff. According to multiple health sources, including Healthline and Medical News Today, this infection is a leading culprit.
!Image of Clostridioides difficile bacteria under a microscope Image Source: CDC/ Lois S. Wiggs (PHIL #6260), 2004, via Wikimedia Commons
C. diff is a bacterium that can cause inflammation of the colon (colitis). It often flourishes when the natural balance of your gut bacteria is disrupted, most commonly after a course of antibiotics.
Symptoms and Risk Factors for C. diff
The distinct sweet smell is often accompanied by other, more prominent symptoms:
- Watery diarrhea (at least three bowel movements per day for two or more days)
- Fever
- Stomach tenderness or cramping
- Loss of appetite
- Nausea
Key risk factors for a C. diff infection include:
- Recent or current use of antibiotics
- Being over the age of 65
- A recent stay in a hospital or nursing home
- Having a weakened immune system
If you have these symptoms and risk factors, it is crucial to contact a doctor for proper testing and treatment.
Can Your Diet Cause Sweet-Smelling Feces?
Your diet is one of the biggest factors influencing the smell of your stool. The bacteria in your gut break down the food you eat, producing various gases and compounds that contribute to the final odor.
High-Sugar Foods and Sweeteners
According to medical resources like Ubie Health, a diet high in sugar or artificial sweeteners can alter your gut's microbial balance. This shift can lead to the production of different chemical compounds during digestion, potentially resulting in a sweeter-than-usual odor.
Malabsorption Issues
Sometimes, a change in stool odor can be related to how your body digests food. Malabsorption occurs when your body can't properly absorb nutrients from your digestive tract. Dr. Xiaocen Zhang, a gastroenterologist at Tufts Medical Center, explains in an article for The Healthy that excessively fatty meals can lead to "fatty stool" (steatorrhea), which has a particularly foul, rancid smell due to undigested fat. While not typically described as "sweet," any significant change in digestion can lead to unusual odors.
The Debated Link with Diabetes
A common question is whether sweet-smelling feces could be a sign of diabetes. The evidence here is conflicting and generally weak.
Most medical experts agree that sweet-smelling feces is not a standard or reliable symptom of diabetes. As noted by Sinocare, the well-established "sweet" symptoms of uncontrolled diabetes are:
- Fruity-smelling breath: This is a sign of diabetic ketoacidosis (DKA), a serious condition where the body produces excess ketones.
- Sweet-smelling urine: This occurs when the body tries to expel excess sugar through urination.
Theories suggesting that unabsorbed sugar in the gut or ketones could affect stool odor remain speculative and lack strong scientific backing. Therefore, while people with diabetes should monitor any changes in their body, sweet-smelling stool alone should not be considered a primary indicator of the condition.
Other Potential Causes
Sweet-Smelling Stool in Infants
For new parents, it's worth noting that the stool of a breastfed baby can sometimes have a mild, sweet odor. The Australian Breastfeeding Association states this is normal and usually changes once formula or solid foods are introduced.
Rare Genetic Conditions
In very rare instances, certain genetic metabolic disorders can cause unusual body odors. For example, Maple Syrup Urine Disease (MSUD) causes a sweet, maple syrup-like smell in urine and sweat. While the effect on stool is less documented, it highlights how metabolic processes can influence bodily scents.
When to Be Concerned: A Timeline for Monitoring
While a temporary change in stool odor is often harmless, persistence or accompanying symptoms are key indicators that you should seek medical advice.
See a Doctor Immediately If You Experience:
- Persistent, watery diarrhea alongside the sweet smell.
- A high fever.
- Severe abdominal pain, cramping, or tenderness.
- Blood in your stool, which may look bright red or like black tar.
- Signs of dehydration, such as minimal urination, extreme thirst, and dizziness.
Monitor at Home If:
The sweet smell is the only symptom and is not severe. You can:
- Review your recent diet: Have you eaten more sugary foods or tried new processed items?
- Stay hydrated: Drink plenty of water.
- Keep a symptom diary: Note the frequency, consistency, and odor of your bowel movements for a few days.
Schedule a Doctor's Appointment If:
- The sweet smell persists for more than a few days without a clear dietary reason.
- You experience other persistent symptoms like unexplained weight loss, ongoing fatigue, or a lasting change in bowel habits.
In Conclusion
The most common and concerning cause of distinctly sweet-smelling feces is a C. diff infection, especially if you have recently taken antibiotics. However, dietary factors often play a significant role in temporary changes to your stool's odor. While the link to diabetes is not well-supported, it's always wise to be aware of your body's signals.
If you are ever in doubt, or if the change is persistent and accompanied by other symptoms, do not hesitate to consult a healthcare provider. They can perform the necessary tests to give you an accurate diagnosis and peace of mind.
References
- Frothingham, S. (2019). What's Causing My Sweet Smelling Poop? Healthline. https://www.healthline.com/health/sweet-smelling-poop
- Sissons, B. (2023). Sweet-smelling stool: Causes and more. Medical News Today. https://www.medicalnewstoday.com/articles/sweet-smelling-stool
- Ubie Health. (2025). Why does my poop smell sweet? Ubie Doctor's Note. https://ubiehealth.com/doctors-note/sweet-poop-odor-reasons
- Cleveland Clinic. (n.d.). C. diff (Clostridioides difficile) Infection. https://my.clevelandclinic.org/health/diseases/15548-c-diff-infection
- Zhang, X. (2025). If Your Poop Smells Different Than Usual, Here’s What It Means According to an Expert Doctor. The Healthy. https://www.thehealthy.com/digestive-health/why-does-my-poop-smell-different-an-expert-doctor-explains/
- Huang, A. Is Sweet-Smelling Poop a Sign of Diabetes? Sinocare. https://en.sinocare.com/blogs/diabetes/is-sweet-smelling-poop-a-sign-of-diabetes
About the author
Fatima Al-Jamil, MD, MPH, is board-certified in gastroenterology and hepatology. She is an Assistant Professor of Medicine at a university in Michigan, with a clinical focus on inflammatory bowel disease (IBD) and motility disorders.