Diabetes can cause a range of complications, such as neuropathy, or nerve damage, and bacterial overgrowth. These complications, along with some diabetes medication, can increase the risk of diarrhea.

In a person with diabetes, the body has difficulty regulating blood sugar levels due to problems with insulin. This can lead to high blood sugar levels, or hyperglycemia and a range of complications, including nerve damage, or diabetic neuropathy.

Diabetic enteropathy is a type of nerve damage that affects the digestive system. Up to one in five people with this complication will experience diarrhea, according to a study published in 2016.

Persistently high blood sugar and the length of time a person has had diabetes are two factors that affect the chances of having neuropathy and diarrhea. Diarrhea can also be a side effect of some diabetes medications.

Chronic, or long-term, gastrointestinal problems can bring further complications.

It is important for a person with diabetes and diarrhea to speak to a doctor, who will help them to find a solution.

Diabetes and some of its complications can affect the digestive system, leading to persistent diarrhea.


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Diabetic diarrhea can affect a person’s quality of life.

The symptoms of diabetic enteropathy include:

  • feeling full after eating
  • nausea
  • bloating
  • abdominal pain
  • diarrhea, constipation or both

A case study, reported in Diabetes Care, describes a man who had watery bowel movements, especially at night, with fecal incontinence. He experienced over 15 bowel movements in 24 hours over 2–3 days, followed by constipation for 4–5 days.

Diabetic diarrhea is different than other forms of diarrhea, although it can be hard to distinguish from other types.

It can occur during the day or night, and it can impact a person’s quality of life and social interaction.


A person with diabetes has high blood sugar levels due to a problem with insulin. Persistently high blood glucose levels can lead to a range of problems and complications, including neuropathy.

Autonomic neuropathy is nerve damage that affects the automatic nervous system (ANS), the system that controls functions such as digestion and breathing.

Neuropathy that affects the digestive system is diabetic enteropathy. Nerve damage in the gastrointestinal tract can impact the consistency and frequency of bowel movements and lead to diarrhea, constipation, and other problems.

Bacterial overgrowth can contribute. The movement of fluids and foods through the digestive system can slow down, creating a good environment for bacteria to grow. This, too, can contribute to diarrhea symptoms.

Exocrine pancreatic insufficiency (EPI) can also occur in people with diabetes. In EPI, the pancreas does not produce enough digestive enzymes. This deficiency, in turn, interferes with digestion.

A 2011 study showed that, on average, EPI affects 51 percent of people with type 1 diabetes and 32 percent of people with type 2.

The American Diabetes Association estimate that 10 percent of people with type 1 diabetes also have celiac disease. People with this condition cannot tolerate gluten. Eating cereal products, including many types of bread, can result in gastrointestinal symptoms, including diarrhea.

People with diabetes should check with a doctor in case long-term diarrhea has become a health issue.

Side effects of diabetes medication

Various long-term treatments for diabetes might lead to severe and persistent diarrhea.

Metformin is a medication for treating type 2 diabetes. It is effective for treating diabetes, but up to 10 percent of people who use it experience side effects in the gastrointestinal system. One of these side effects is diarrhea.

The adverse effects of metformin may resolve in time. Some people, however, might need to stop taking the medication if the diarrhea does not go away.

Other diabetes medications that can have a similar effect include GLP-1 receptor agonists and DPP-4 inhibitors, as well as statins.


In May 2020, the Food and Drug Administration (FDA) recommended that some makers of metformin extended release remove some of their tablets from the U.S. market. This is because an unacceptable level of a probable carcinogen (cancer-causing agent) was found in some extended-release metformin tablets. If you currently take this drug, call your healthcare provider. They will advise whether you should continue to take your medication or if you need a new prescription.

Treatment for diarrhea depends on the cause.

Diabetic diarrhea can be difficult to treat if it results from damage to the nervous system. However, managing high blood glucose levels may help to prevent the damage and diarrhea from worsening.

If the underlying cause is bacterial overgrowth, treatment will aim to reduce the number of bacteria in the body and allow healing time.

A doctor may recommend antidiarrheal medications, such as loperamide.

Preventing dehydration

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woman drinking water for diarrhea

Dehydration is a major risk for anyone with diarrhea, whatever the cause.

To prevent dehydration, a person should:

  • replace any lost fluids by drinking plenty of water
  • receive fluids in the hospital if symptoms are severe
  • use an oral rehydration solution (ORS) to replenish salts and other substances that the body needs

Untreated, dehydration can be life-threatening.

Other treatments include:

  • Over-the-counter (OTC) medication: Imodium or Pepto-Bismol may help to reduce stool liquidity.
  • Antibiotics: If bacterial overgrowth is causing diarrhea, a doctor might prescribe antibiotics.
  • Probiotics: Some food containing “good” bacteria, such as lactobacilli, have demonstrated helpful effects on infectious diarrhea, reducing recovery time for 21 in every 100 people in one 2016 study.
  • Dietary changes: High-potassium foods and drinks, such as potatoes, bananas, and diluted fruit juices without added sugar may help.

A person with diabetes should check the label of any over-the-counter medications they use and ask their doctor to recommend one that is suitable for them.

Click here to find out more about home remedies for diarrhea.

Some foods may worsen the symptoms of diarrhea.

Avoiding the following may help to stop this from happening:

  • fried and greasy foods
  • gassy foods, such as broccoli, beans, and prunes
  • sugar alcohols, used to replace sugar in some products
  • milk, if intolerant to lactose
  • caffeine
  • alcohol
  • carbonated sodas

Find out more here about how some foods can cause diarrhea.

A doctor will ask questions, and they may do some tests to try to find out the cause of the diarrhea. This will affect any decisions about treatment options.

The person should be ready to tell the doctor:

  • when the diarrhea started
  • any medication that may have altered the stool
  • the frequency and consistency of bowel movements
  • if blood is present in the stool
  • if nausea and vomiting also occur

Keeping a food diary may help to identify specific triggers.

Diabetic diarrhea may:

  • occur intermittently rather than all the time
  • alternate with regular bowel movements
  • occur during the day and night
  • be painless

Diabetic diarrhea is difficult to diagnose because a range of causes often work together. It can also be hard to distinguish it from other causes and types of diarrhea.

    If a person has diarrhea or other digestive symptoms, they should talk to a physician. If the diarrhea persists without treatment, further complications can arise.

      The doctor may carry out tests to find out if the diarrhea is due to diabetes or another condition, such as celiac disease or a lactose intolerance.

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      Managing diabetes can help to prevent complications.

      People with diabetes might find it difficult to prevent diarrhea, as complications such as autonomic neuropathy require wide-ranging, ongoing management.

      Keeping blood sugar levels steady through activity, a healthful diet, and the use of any recommended medications can help to stop diabetes complications from developing or getting worse.

      The following steps might reduce the risk or impact of diarrhea symptoms:

      • Drink clean water: Use boiled or bottled water if local water sources may not be clean.
      • Follow good handwashing practices: Wash the hands with soap and warm water after touching public places, using the bathroom, helping a child use the toilet, before eating, and before and after preparing food.
      • Hand rub: Use an antibacterial hand rub when soap and water is unavailable. This can reduce the risk of diarrhea from bacterial causes.

      People with long-term diarrhea should track their symptoms and discuss them with a doctor to determine and treat the underlying cause.


      What are the main differences between diabetic diarrhea and other types?


      Other types of diarrhea may be more easily treatable and temporary than diabetic diarrhea.

      For example, if diarrhea occurs due to acute gastroenteritis, a viral infection, your body tends to resolve the diarrhea without active treatment. Viral gastroenteritis may cause abdominal pain, nausea, vomiting, and fever.

      If a person has celiac disease or lactose intolerance, dietary changes usually help to keep diarrhea and associated symptoms at bay, such as abdominal bloating. Uncontrolled diabetes mellitus, however, could cause chronic problems in the GI tract, possibly with recurring episodes of diarrhea.

      Diarrhea related to diabetes is typically a progressive process once it sets in.

      Additionally, diabetic diarrhea may be painless. The evaluation and treatment for diabetic diarrhea may not be as simple as diagnosing other causes of diarrhea. If you find yourself with episodes of diarrhea that do not resolve over time, a physician can help you figure out the cause and find the appropriate treatment.

      If you have diabetic diarrhea, the treatment approach will likely have multiple factors and will include trying to manage your blood glucose levels.

      Stacy Sampson, DO Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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