If you have diabetes, and you also have gut issues, like diarrhea, constipation, gas, and bloating, you’re certainly not alone. As many as 75 percent of people with diabetes also report having issues with their stomach or digestion.

Diabetes and irritable bowel syndrome (IBS) are both fairly common conditions, and it’s possible to have both at the same time. In fact, the two conditions may be related. Diabetes can damage the nerves around the gut and lead to symptoms of IBS, such as:

  • diarrhea
  • constipation
  • excess gas
  • stomach pain

Some diabetes medications, as well as some foods that people with diabetes eat, such as foods high in fiber and sugar alcohols like sorbitol, can also affect the bowels, leading to diarrhea or constipation.

With a little extra effort, both IBS and diabetes can be managed through diet, medications, and stress reduction.

Diabetes and irritable bowel syndrome are two different conditions, and it’s possible to have them both.

IBS

IBS is a gastrointestinal disorder characterized by a group of symptoms that typically occur together. These symptoms may include:

  • diarrhea
  • gas
  • cramping or pain
  • constipation
  • bloating

IBS is thought to be related to problems with how your brain and your gut work together.

Diabetes

Diabetes occurs when your body can’t make enough of the hormone insulin or can’t use insulin effectively. Diabetes is a systemic disease. This means it affects many parts of the body at once.

People with diabetes have higher than normal levels of sugar (glucose) in the blood. This is known as hyperglycemia. Over time, high blood sugar can lead to complications in many parts of the body, including the gastrointestinal tract.

Many people with diabetes complain of:

  • early satiety, or feeling full
  • acid reflux
  • constipation
  • stomach pain
  • nausea
  • vomiting
  • diarrhea

Over time, high blood sugar from diabetes can cause damage to the nerves, called neuropathy, in the gastrointestinal tract. This can impair your brain’s ability to communicate with your gut.

The damage can cause a slowing down or speeding up of intestinal function, leading to either constipation or diarrhea — common symptoms of IBS.

There are other ways that high blood sugar can lead to gastrointestinal symptoms:

  • High blood sugar may slow down the emptying of the stomach, leading to fullness, nausea, and bloating.
  • People with diabetes are at a higher risk of developing yeast infections in the GI tract or bacterial overgrowth.
  • Diabetes makes it harder to properly break down sugars in the small intestine.
  • A serious complication of diabetes known as ketoacidosis can cause stomach pain.
  • Nerve damage in the esophagus may cause heartburn and make it difficult for you to swallow.
  • People with type 1 diabetes have a higher risk of a condition called celiac disease. People with this condition can’t tolerate gluten, a protein found in wheat, rye, and barley. Eating gluten can cause GI symptoms, such as diarrhea.

In general, it’s best for people with diabetes to eat healthy foods with a high fiber content, like whole grains and vegetables, to help stabilize blood sugar levels. People with diabetes should try to avoid highly processed foods and foods high in sugar.

Some people with IBS may also benefit from a high fiber, low sugar diet, but sometimes foods high in fiber can trigger symptoms of IBS. Foods high in fiber include:

  • nuts
  • seeds
  • fruits
  • vegetables
  • legumes

If you have diarrhea

If you tend to have diarrhea as a result of IBS or diabetes, you may want to reduce the amount of soluble fiber in your diet. Soluble fiber is found in foods such as:

  • oats
  • bananas
  • carrots
  • apples
  • barley

If you have constipation

If you tend to get constipated as a result of IBS or diabetes, you may want to increase your intake of insoluble fiber, which is found in foods like:

  • whole grains
  • wheat bran
  • cereals
  • nuts
  • potatoes

Foods to avoid

Many people with IBS experience symptoms when they eat certain types of vegetables called cruciferous vegetables. Examples include:

  • broccoli
  • Brussels sprouts
  • cabbage
  • cauliflower

Legumes, such as beans, may also trigger symptoms of IBS, though this isn’t true for everyone. You may need to keep a food diary to track which foods trigger your symptoms.

Be careful with sugar substitutes

Many people with diabetes try to limit their sugar intake, so they instead opt for sugar substitutes. Unfortunately, many of these are linked to GI symptoms and may need to be avoided if you have both diabetes and IBS.

Sorbitol and xylitol are two sugar substitutes that have been linked to GI symptoms. A good substitute for people with IBS and diabetes is a natural sweetener known as stevia.

Lifestyle changes to try

You may be able to alleviate symptoms of both diabetes and IBS by making the following changes to your diet and lifestyle:

  • avoiding processed foods
  • avoiding foods high in sugar
  • increasing fiber intake
  • avoiding alcohol
  • adapting to a special eating plan known as a low FODMAP diet
  • increasing physical activity
  • reducing stress

IBS may make it difficult for your body to digest food at a normal rate. Because of this, blood sugar levels may be unpredictable after a meal. Checking your blood sugar levels before and after a meal can help you determine how your body responds.

Both constipation, which is too few bowel movements, and diarrhea, which is frequent, loose bowel movements, are common in people with diabetes.

It’s estimated that around 20 percent of people with diabetes experience frequent diarrhea, while up to 60 percent of people with diabetes experience constipation.

Fecal incontinence, a loss of bowel control, may also occur in people with diabetes.

Gastroparesis

Gastroparesis is a digestive condition characterized by delayed gastric emptying. This means that food stays in the stomach for too long rather than moving into the small intestine to be digested further.

Diabetes is the leading cause of gastroparesis. High blood sugar from diabetes can damage the vagus nerve — the nerve that connects the brain to the gastrointestinal tract.

When this happens, the vagus nerve can no longer send messages that tell the stomach muscles to empty the stomach.

Symptoms of gastroparesis include:

  • nausea
  • reduced appetite
  • feeling full after eating small amounts of food
  • vomiting
  • stomach pain
  • heartburn

Metformin is the most widely used oral type 2 diabetes medication. People newly diagnosed with type 2 diabetes are often prescribed metformin to manage their blood sugar.

Some people who start taking metformin experience side effects in the digestive tract like diarrhea, nausea, and abdominal pain. These symptoms typically go away over time as the body adjusts to the medication. You can reduce these effects by taking metformin with a meal.

You should see your doctor if you’re experiencing frequent diarrhea or constipation or both, or you’re having trouble managing your blood sugar levels with diet, exercise, and medications.

A medical professional will want to know about your symptoms and any medications that you’re taking.

If you have diabetes, IBS symptoms like diarrhea, constipation, and bloating could mean that blood sugars are not under control. Long-term, this can lead to nerve damage in the GI tract.

However, these symptoms could also be tied to eating certain foods, consuming sugar alcohols, or taking certain diabetes medications, such as metformin.

See a medical professional if you’re experiencing frequent diarrhea or constipation or having trouble managing your blood sugar levels. The earlier you treat diabetes, the less likely you’ll be to develop more serious complications, such as nerve damage and gastroparesis.