Does Diabetes Cause Diarrhea?

Diabetes has many well-known side effects, but lots of people don’t realize that diarrhea is a common one. In fact, approximately 75% of people with diabetes have some form of gastrointestinal symptoms, which can have a big impact on your life and well-being.

Chronic diarrhea lasts at least four weeks, with bouts of diarrhea coming and going. Oftentimes, diarrhea occurs at night and is severe, with lots of liquid stool. Diabetic diarrhea is also associated with incontinence—the inability to control output—which may cause someone to soil themselves.

Here’s what you should know about diabetic diarrhea, including causes, diagnosis, and treatments. 

Diabetic Diarrhea Cause

Doctors have known about diabetic diarrhea since the 1930s, but they still aren’t sure about why diabetic diarrhea is so common. It seems there are multiple factors at play, including:

• Nerve damage
• Diet
• Side effects from medication

Some or all of those might be affecting you if you’re a diabetic with chronic diarrhea. 

Neuropathy

Many people realize that 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 short 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 doctor about any new symptoms so that the doctor can help you control your sugars more effectively. 

Sorbitol

Sorbitol is an artificial sweetener that can be used by diabetics 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 diabetic diarrhea because it’s also a laxative.

Enteric Nervous System Damage

The enteric nervous system (ENS) controls the digestive tract. Diabetes can damage the ENS, increasing the risk for gastrointestinal issues, including diarrhea.

Celiac Disease

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.

Certain Foods

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

Does Metformin Cause Diarrhea?

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 a type 2 diabetic on metformin who is experiencing chronic diarrhea, talk to your doctor about whether there are other options available to help control your blood sugar. 

Risk Factors

Certain factors increase your risk for diabetic diarrhea. Diarrhea is more common in people with:

• Type 1 diabetes
• Insulin dependence
• Many years’ history of diabetes, especially those who have been insulin-dependent for more than eight years
• Older people

Treatments

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

• Antidiarrheal medications 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 doctor about the factors that might be contributing, and how you might keep symptoms at bay. 

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 minimize symptoms. In addition, if you have type 1 diabetes, you should be screened for celiac disease, since you have an increased risk.

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 doctor can help identify the factors that are contributing to your diarrhea, and what might be done to alleviate it. 

Remember that the best thing you can do to prevent your diarrhea from getting worse is to keep your blood sugars stable. This will reduce neuropathy, and help you maintain function and control of your digestive system. 

Diabetic diarrhea isn’t something you have to live with. Through medication, lifestyle changes, and guidance from your doctor, you should be able to lessen the impact of diabetic diarrhea.