Diabetes and diarrhea: What’s the connection?

If you’re living with diabetes and experiencing frequent diarrhea, you’re not alone. While it may feel unrelated at first, diabetes and diarrhea can go hand-in-hand — especially for those with long-standing or poorly controlled blood sugar levels.

In this article, we’ll explain why diarrhea happens more often in people with diabetes, how to tell if it's linked to your condition, and what you can do to find relief.

Is diarrhea common in people with diabetes?

Yes, studies show that up to 20% of people with diabetes experience chronic or intermittent diarrhea. It’s more common in people with type 1 diabetes, but those with type 2 can experience it too.

Episodes may occur several times a week, especially at night, and can alternate with periods of normal bowel movements or constipation.

What causes diarrhea in diabetes?

Several diabetes-related factors can contribute to diarrhea:

1. Autonomic neuropathy

This occurs when long-term high blood sugar damages the nerves that control digestion. It can lead to:

• Poor coordination of intestinal muscles

• Rapid transit of stool

• Bloating and discomfort

2. Medication side effects

Some diabetes medications can cause digestive symptoms, especially:

• Metformin (common cause of diarrhea)

• GLP-1 receptor agonists (like Ozempic or Trulicity)

• Antibiotics used for infections

3. Sugar alcohols

Artificial sweeteners like sorbitol and xylitol, often found in “diabetic-friendly” products, can cause gas, bloating, and loose stools.

4. Bacterial overgrowth

People with diabetes may have delayed digestion, leading to small intestinal bacterial overgrowth (SIBO), which can trigger diarrhea.

5. Celiac disease or other GI conditions

Some people with type 1 diabetes may also have autoimmune gut conditions like celiac disease, which causes diarrhea when gluten is consumed.

How do I know if diabetes is causing my diarrhea?

Here are a few signs that your diarrhea may be related to diabetes:

• You have long-standing diabetes (usually 5+ years)

• Diarrhea occurs at night or without warning

• Episodes are chronic (lasting several weeks or recurring frequently)

• You also experience signs of nerve damage (numbness, tingling, slow digestion)

Still, it’s important to rule out other causes. Talk to your doctor if symptoms last more than a few days or interfere with daily life.

What does diabetic diarrhea feel like?

It may feel like:

• Loose, watery stools (often without warning)

• Urgency and frequent bathroom trips

• Bloating or gas

• Disrupted sleep due to nighttime bowel movements

• Fatigue from dehydration or poor nutrient absorption

Some people experience alternating diarrhea and constipation, especially if nerve damage is involved.

When should I see a doctor?

Get checked out if you notice:

• Diarrhea lasting more than 2–3 days

• Blood in your stool

• Unintentional weight loss

• Fever or chills

• Signs of dehydration (dry mouth, dizziness, fatigue)

Your doctor can evaluate whether the cause is related to diabetes, medication, or another condition.

How is diabetic diarrhea diagnosed?

Your provider may order:

• Blood tests to rule out infections or inflammation

• Stool tests for bacteria, parasites, or fat malabsorption

• Gluten sensitivity or celiac disease screening

• Breath tests to check for bacterial overgrowth (SIBO)

• Colonoscopy or imaging if other causes are suspected

They’ll also review your medications and ask about your diabetes control history.

How is diabetic diarrhea treated?

Treatment depends on the underlying cause. Options may include:

Adjusting medications

• Switching from metformin to an extended-release version

• Changing GLP-1 doses or timing

• Reviewing other GI-irritating meds

Diet changes

• Avoid artificial sweeteners (like sorbitol, mannitol, xylitol)

• Keep a food diary to spot triggers

• Eat smaller meals with lower fat content

Managing SIBO or infections

• Antibiotics (like rifaximin) may help with bacterial overgrowth

Controlling blood sugar

• Stable glucose levels support better nerve and gut function

Antidiarrheal medications

• Loperamide (Imodium) may be used occasionally, with medical supervision

Probiotics

• Certain strains like Saccharomyces boulardii or Lactobacillus may help restore gut balance
  
  

Can I prevent diarrhea if I have diabetes?

Yes — here are a few ways to reduce your risk:

• Keep blood sugar in target range

• Stay hydrated (especially if using fiber supplements)

• Avoid foods or drinks with sugar alcohols

• Introduce new diabetes meds slowly

• Monitor for signs of GI upset when changing your routine

Can chronic diarrhea cause complications?

Yes. Ongoing diarrhea can lead to:

• Dehydration

• Electrolyte imbalances (like low potassium or sodium)

• Nutrient malabsorption

• Unintentional weight loss

• Fatigue and weakness

That’s why identifying the cause early and treating it is key to protecting your long-term health.

Takeaway

If you have diabetes and struggle with diarrhea, it’s more than just an inconvenience — it could be a sign of nerve damage, medication side effects, or digestive imbalance. While not everyone with diabetes experiences diarrhea, up to one in five people do, and many suffer in silence. The good news is that identifying the cause can lead to real relief. Whether it’s adjusting your medications, fine-tuning your diet, or treating an underlying gut condition like SIBO, there are proven ways to improve your symptoms. It starts with listening to your body, tracking patterns, and talking with your healthcare provider. Managing your blood sugar and gut health together is the key to feeling better — inside and out.

Take the next step

Experiencing diarrhea with diabetes? Our gut and glucose combo test can help you get personalized answers and actionable guidance — all from home.

Check out our test kits

Related Resources

Want to understand more about how diabetes affects your body? Try these guides:

• Is Feeling Sleepy After Eating a Sign of Diabetes? – Digestive and fatigue signs explained.

• Diabetes and Swollen Feet – Learn how diabetes impacts circulation.

• Does Diabetes Cause Hair Loss? – Explore lesser-known complications.

References

References

Boland, B. S., Edelman, S. V., & Wolosin, J. D. (2013). Gastrointestinal Complications of Diabetes. Endocrinology and Metabolism Clinics of North America, 42(4), 809–832. https://doi.org/10.1016/j.ecl.2013.07.006 

Clinic, C. (2023, September 9). Diabetes-Related Diarrhea: Metformin Diarrhea, Diabetes-Related Autonomic Neuropathy. Retrieved September 17, 2025, from Cleveland Clinic website: https://my.clevelandclinic.org/health/symptoms/22843-diabetic-diarrhea 

Malins, J. M., & Mayne, N. (1969). Diabetic Diarrhea: A Study of Thirteen Patients with Jejunal Biopsy. Diabetes, 18(12), 858–866. https://doi.org/10.2337/diab.18.12.858 

NHS website. (2025, February). Complications of type 2 diabetes. Retrieved September 17, 2025, from nhs.uk website: https://www.nhs.uk/conditions/type-2-diabetes/complications/ 

Ogbonnaya, K. I. (1990). Diabetic diarrhea. Pathophysiology, diagnosis, and management. Archives of Internal Medicine, 150(2), 262–267. https://doi.org/10.1001/archinte.150.2.262 

Pointer, K. (2016, May 11). Is Diarrhea a Symptom of Diabetes? Retrieved September 17, 2025, from Healthline website: https://www.healthline.com/health/diabetes/diabetes-and-diarrhea 

 

 

 

Frequently Asked Questions

Q: Why does diabetes cause diarrhea?

A: Nerve damage from diabetes, certain medications, or bacterial overgrowth in the gut can lead to diarrhea.

Q: Is diarrhea common in people with diabetes?

A: It can be. Chronic diarrhea is seen more in people with long-standing, poorly controlled diabetes.

Q: What should I eat if I have diabetes-related diarrhea?

A: Stick to bland, easy-to-digest foods like rice, bananas, toast, and clear fluids while managing blood sugar.

Q: When should I see a doctor about diarrhea and diabetes?

A: If diarrhea is persistent, severe, or leads to dehydration, consult a healthcare provider promptly.