Can Diarrhea Be a Symptom of Diabetes?

Diarrhea is common among people living with diabetes, with about 75% of them reporting some type of gastrointestinal (digestive) symptoms. Chronic diarrhea, often seeming worse at night, may occur. Diabetic diarrhea is also associated with fecal incontinence.

Causes of diarrhea with diabetes can include diet or medications like Glucophage (metformin), used to treat type 2 diabetes. Diarrhea is more likely among people taking insulin for type 1 diabetes, older people, and those also diagnosed with celiac disease.

This article explains why diarrhea can occur when living with diabetes. It discusses causes and risk factors for diarrhea, how it is diagnosed and treated, and when it's important to see a healthcare provider.

What Is Diarrhea?

Diarrhea is defined as having loose or watery bowel movements that occur three or more times per day. There are many possible causes but if the diarrhea lasts for more than two days, it may be related to a more serious problem than a passing stomach bug or foodborne illness.

Chronic diarrhea is defined as lasting four or more weeks. A number of causes and conditions can lead to chronic diarrhea, including:

• Irritable bowel syndrome, a digestive disorder linked to muscle function in the colon
• Certain medications, nutrient deficiencies, or digestive malabsorption conditions
• Infections, including bacterial Clostridioides difficile (C. difficile) and parasitic giardiasis

Endocrine disorders, including hyperthyroidism (an overactive thyroid) and diabetes, are common causes of gastrointestinal symptoms like diarrhea.

Is Diarrhea a Symptom of Diabetes?

Diarrhea has been identified as a symptom of diabetes since the 1930s, but healthcare providers still aren’t sure why diabetic diarrhea is so common. It seems there are multiple factors at play, including:

• Nerve damage (neuropathy)
• Diet, including artificial sweeteners
• Side effects from medication

Some or all of those might be affecting you if you have diabetes and experience chronic diarrhea. 

Nerve Damage

Diabetes can cause neuropathy—or nerve damage. Most often, diabetic neuropathy is associated with a loss of feeling in the feet or legs. However, diabetic neuropathy can also cause a loss of sensation in the nerves that affect the internal organs. This is known as autonomic neuropathy.

When neuropathy occurs in the small intestine it can lead to diabetic diarrhea. If you have neuropathy in the sphincter muscles that control the bowel, you might experience incontinence in addition to diarrhea.

Neuropathy is closely linked with high blood sugar levels. If you have diabetes, it’s critical to keep your blood sugar levels well controlled to avoid developing or worsening neuropathy. Be sure to communicate with your healthcare provider about any new symptoms so that the practitioner can help you control your sugars more effectively. 

Diet and Diarrhea

Certain foods can cause diarrhea, even in individuals without diabetes. If you have diabetic diarrhea you might choose to avoid these foods, including:

• Spicy foods
• Caffeine
• Dairy

Diet-related health conditions also may contribute to diarrhea. About 6% of people with type 1 diabetes also have celiac disease. That’s about six times higher than the rate in the general population. If you have celiac disease your body cannot tolerate gluten. Eating it can cause your body to attack the lining of the small intestine, leading to diarrhea.

Sorbitol is an artificial sweetener that can be used by people with diabetes who are looking to reduce their sugar intake. It’s beneficial because it provides sweetness without a spike in blood sugar. However, sorbitol can contribute to diarrhea because it’s also a laxative.

Side Effects of Medication

Diarrhea is a side effect of many medications, including antibiotics and antidepressants.

Many people with type 2 diabetes use the medication metformin to help control their blood sugar. Diarrhea is a common side effect when a person first begins taking metformin. Occasionally, people will experience chronic diarrhea after they’ve been on the medication for a long time, even years.

If you are taking metformin to treat type 2 diabetes and experience chronic diarrhea, talk to your healthcare provider about whether there are other options available to help control your blood sugar. 

Treatments and Management of Diarrhea

Your healthcare provider should be able to prescribe a treatment plan to control the symptoms of your diabetic diarrhea. This might include:

• Antidiarrheal medications, like Imodium (loperamide), to slow down the movement of stool
• Antispasmodic medicine to reduce how often you have bowel movements
• Dietary changes including eating more fiber, and avoiding certain foods and artificial sweeteners that can make diarrhea worse

If your diarrhea is associated with ENS damage, treatment with serotonin receptor antagonists may help restore more normal function in the digestive tract.

If you are experiencing diabetic diarrhea, talk to your healthcare provider about the factors that might be contributing and how you might keep symptoms at bay. 

When to See Your Healthcare Provider

Diarrhea that lasts two days or more should be evaluated by a healthcare provider, especially if other symptoms such as a fever are present. Diarrhea can lead to dehydration and other complications, so it's important to be sure it's diagnosed and treated.

See your healthcare provider if you experience diarrhea along with:

• Nausea and vomiting
• Severe abdominal or rectal pain
• Black and tarry stools, or diarrhea that contains blood or pus

You should talk to your healthcare provider about diabetic diarrhea for additional reasons. That's because diarrhea and other gastrointestinal symptoms in people living with diabetes suggest long-term concerns and underlying conditions. They include:

• Poor glucose (blood sugar) control
• Potential nutritional deficiencies
• A greater risk of cardiovascular disease (CVD), including high blood pressure (hypertension)
• A higher risk of diabetic retinopathy

Prevention

You can take steps to prevent diabetic diarrhea, even before you begin experiencing it. One of the most significant steps you can take is to keep your blood sugars within your target range. Keeping blood sugar stable will reduce your risk for neuropathy, including the autonomic neuropathy that can contribute to diabetic diarrhea.

Changing your diet to avoid foods that trigger your diarrhea can also help to minimize symptoms. In addition, if you have type 1 diabetes, you should be screened for celiac disease, since you have an increased risk.

Summary

People with diabetes commonly experience diarrhea symptoms, although the exact causes of diabetic diarrhea remain unclear and differ among individuals. Diet, medication, and digestive system nerve damage due to neuropathy all may contribute to the condition.

While your diarrhea may cause discomfort and seem merely unpleasant, diabetic diarrhea may be a sign of more serious problems, including blood sugar levels that need better control. It also suggests the potential for other complications like diabetic retinopathy.

Your healthcare provider can help you to keep your blood sugar levels stable and reduce impacts to your digestive system. Through medication and lifestyle changes, you may be able to limit your diabetic diarrhea symptoms.  

A Word From Verywell

Experiencing diarrhea can be embarrassing, especially if it is accompanied by incontinence. It can be difficult to talk about such a private bodily process, but speaking openly with your healthcare provider can help identify the factors that are contributing to your diarrhea and what might be done to alleviate it.