Link between diabetes and loose stools or diarrhea

Do you or your loved one have diabetes and notice that you often pass loose stools? This article is for you, as it discusses the possible causes of loose stools and diarrhea in people with diabetes. 

Image showing the stomach and intestines

Key takeaways:

  • Diabetes is associated with diarrhea, which can cause people with the condition to pass loose stools. Health issues like bacterial overgrowth, celiac disease, and even certain diabetes medications can cause diarrhea and, ultimately, loose stools in people with diabetes. 
  • Doctors prescribe medications like loperamide and octreotide acetate injections to treat diarrhea in patients with diabetes. These medications help control bowel movements and stop the passage of loose stools.
  • People with diabetes who have diarrhea should still prioritize maintaining their blood sugar levels. Eating more fiber-rich foods and fewer artificial sweeteners can help them achieve this while aiding proper bowel movement.

Loose stools occur when bowel movement or stool is softer or more watery than usual. Something as simple as the kind of food a person consumes can cause loose stools, and when they pass loose stools more than three times in a day, it may be an indication that they have diarrhea

Diabetes is a chronic (life-long) medical condition that occurs when the pancreas does not produce enough insulin, a hormone that controls the amount of sugar in your blood, or the body does not use insulin as it should, leading to a high blood sugar level.

Some common symptoms of diabetes include frequent urination that often occurs at night, increased thirst, slow healing of cuts and wounds, sores, fatigue, and developing skin and vaginal infections more often than usual. 

Can diabetes cause loose stools?

Diabetes often goes hand in hand with diarrhea, a symptom characterized by the frequent passing of loose stools. 

Health experts are not exactly sure if diabetes directly causes loose stools. But evidence suggests that diabetes-related conditions like celiac disease and autonomic neuropathy, as well as diabetes medications, can cause loose stools in people with diabetes.

Notably, studies have shown that diarrhea and other gastrointestinal symptoms are more common among people with diabetes than among people without this medical condition.

Causes of loose stools in people with diabetes

There are different possible causes of diarrhea and loose stools in people with diabetes, including:  

1. Celiac disease

Celiac disease is a chronic disorder of the digestive tract that occurs when you consume gluten—a protein found in grains like wheat, rye, and barley. In people with celiac disease, the immune system launches an attack when it senses the presence of gluten in the small intestine, causing damage that can lead to malnutrition and other health conditions. 

Diarrhea is one of the gastrointestinal symptoms of celiac disease, and according to a recent  2023 research article, type 1 diabetes is commonly linked with autoimmune disorders like celiac disease.  

2. Autonomic neuropathy

Autonomic neuropathy is a collection of symptoms that occurs when the nerves responsible for the body’s automatic functions, such as digestion, blood pressure, and respiration, become damaged. This condition can affect internal temperature regulation, disrupt the normal digestion process, and lead to dysregulation of blood pressure.

Diabetes is one of the causes of neuropathy, and one of the gastrointestinal symptoms of neuropathy is diarrhea. 

3. Diabetes medications

Diabetes medications like metformin, which physicians prescribe to manage diabetes, are helpful, but they are not without side effects. About 2–63% of type 2 diabetes patients experience gastrointestinal complications as an adverse effect of metformin, and some of these gastrointestinal side effects include flatulence, diarrhea, nausea, and abdominal pain. 

4. Bacterial overgrowth

Small-intestine bacterial overgrowth (SIBO) occurs when there’s a higher population of bacteria in the small intestine than usual. Failure of one or more bacterial chemical or mechanical processes can cause this condition. 

One of these mechanical processes is emptying the contents (food and waste) of the small intestine into the large intestine. When this process becomes slower than usual, it can provide a breeding ground for several bacteria.

Some prevalent symptoms of this condition include abdominal pain, bloating, diarrhea, nausea, and vomiting. A recent study shows a 24-35%  prevalence of SIBO in people with type 1 diabetes for more than five years and those with autonomic neuropathy.

5. Exocrine pancreatic insufficiency

Exocrine pancreatic insufficiency (EPI) occurs when the body does not make sufficient digestive enzymes, which are biochemicals responsible for breaking down food, or the digestive enzymes don’t work as they should. Generally, people with EPI find it difficult to absorb fat, and this can lead to digestive symptoms like abdominal pain, bloating, constipation, and diarrhea.

Recent research shows that diabetes is one of the health conditions that can cause EPI.

How long can diarrhea in diabetes last?

Diarrhea in people with diabetes can last for days, weeks, or months. A study involving 1900 patients with diabetes shows that GI symptoms (e.g., bloating, early satiation, and loose bowel movement) were relatively common and lasted up to 3 months in more than half of the patients after a 1-year follow-up.  

However, this condition can be managed with several medications and lifestyle changes to help you go about your daily activities. 

How to treat diarrhea or loose stools if you have diabetes

Before administering any treatment, your doctor has to determine whether the diarrhea you are experiencing is diabetes-related or not, and this is usually done through a thorough diagnosis.  

Here are some treatments your doctor may recommend:

  • Hydrate yourself to replace bodily fluids lost through diarrhea.
  • Use loperamide to manage loose stools.
  • Use antibiotics to control diarrhea caused by bacterial overgrowth.
  • Use antispasmodic medications to control bowel movements.
  • Inject octreotide acetate injections to reduce the frequency of diabetes-related diarrhea.

Before administering appropriate treatment, your doctor will ask you several questions that will aid in the proper diagnosis of diarrhea. Some questions to expect include:

  • How frequent are the diarrhea and bowel movements?
  • What’s the consistency of your stools?
  • Is there blood present?
  • What’s the color of the stool?
  • When does the stooling often happen (daytime or nighttime)?
  • Is nausea and vomiting present?

Your doctor may ask you further questions about your current medications for a more personalized diagnosis. 

What to eat if you have diabetes and diarrhea

Diet is a crucial factor in managing diabetes and diarrhea. When diarrhea starts, your doctor may recommend that you keep a food diary to recognize meals that may contribute to diarrhea. Some other diet tips your medical provider may give you include:

  • Consume more fiber-rich and whole-grain foods.
  • Drink more water
  • Avoid artificial sweeteners like sorbitol

Seeking medical attention

Diabetes is a chronic condition that needs to be well managed, which is why when you start to have diarrhea, you need to see your doctor or a gastroenterologist for a proper diagnosis to determine if your diarrhea is diabetes-related or not. 

If your diarrhea is diabetes-related, your gastroenterologist will recommend some medications and lifestyle practices to improve the condition. Your doctor may also recommend that you see a nutritionist or dietitian to help you eat healthy while managing diabetes and diarrhea.

Wrap up

Diarrhea is a common complication for people with diabetes. While there’s no complete understanding of its cause, research shows that factors like autonomic neuropathy, bacterial overgrowth, celiac disease, exocrine pancreatic insufficiency, and diabetes medications are significant contributors. 

If you have diabetes with diarrhea, your doctor will recommend some medications for you and give you some ideas on the type of food to eat to reduce your symptoms. 

Frequently Asked Questions (FAQs)

Is diarrhea more common in type 1 or type 2 diabetes?

Researchers have yet to compare the prevalence rate of diarrhea among people with type 1 diabetes vs. those with type 2 diabetes. So, no data shows which of the diabetes types is more commonly associated with diarrhea.

Can metformin help with diabetes and diarrhea?

Metformin is effective for managing diabetes; however, it does not work for treating diarrhea. In fact, diarrhea is one of the possible side effects of this medication.

Metformin works by regulating the amount of glucose the liver releases and helping the cells in your body absorb more glucose. It is more effective when combined with regular exercise and an appropriate diet.