From the Guidelines
High blood sugar can cause diarrhea, particularly through mechanisms such as diabetic neuropathy, bacterial overgrowth in the small intestine, and rapid gastric emptying. The relationship between high blood sugar and diarrhea is complex and multifaceted. When blood sugar levels are consistently elevated, it can damage the nerves that control the digestive system, a condition called diabetic neuropathy 1. This nerve damage can lead to alternating bouts of diarrhea and constipation. Additionally, high blood sugar can cause an overgrowth of bacteria in the small intestine, which disrupts normal digestion and leads to diarrhea. People with diabetes may also experience rapid gastric emptying, where food moves too quickly from the stomach to the small intestine, resulting in diarrhea. Some key points to consider include:
- Diabetic neuropathy as a cause of diarrhea in high blood sugar patients 1
- Bacterial overgrowth in the small intestine as a potential mechanism for diarrhea in diabetes patients
- Rapid gastric emptying as a factor contributing to diarrhea in individuals with high blood sugar
- The importance of managing blood sugar levels through medication, diet, and exercise to reduce digestive symptoms such as diarrhea 1. It is essential for individuals experiencing persistent diarrhea and having diabetes or suspecting high blood sugar to consult with their healthcare provider to determine the exact cause and appropriate treatment.
From the Research
High Blood Sugar and Diarrhea
- High blood sugar, particularly in diabetic patients, can be associated with diarrhea due to various factors 2.
- Medications such as metformin, commonly used to treat type 2 diabetes, can cause diarrhea as a side effect 2, 3.
- Diabetic patients are more likely to have associated diseases, such as celiac sprue and microscopic colitis, which can present with diarrhea as the sole complaint 2.
- Ingested sugar-free foods containing sorbitol or other agents can also cause diarrhea in diabetic patients 2.
- Diabetic enteropathy, a condition that affects the nerves and blood vessels in the digestive system, can itself cause diarrhea 2.
Metformin and Diarrhea
- Metformin use is associated with a higher risk of gastrointestinal adverse events, including diarrhea, abdominal pain, and nausea, compared to control 3.
- The risk of bloating and diarrhea is higher with metformin immediate-release than with metformin extended-release formulation 3.
- Metformin is still widely considered to be the optimal initial therapy for patients with type 2 diabetes mellitus, despite its potential side effects 4.
Management of Hyperglycemia and Diarrhea
- The management of hyperglycemia in type 2 diabetes involves a holistic approach, including weight management, physical activity, and social determinants of health 5.
- While the consensus report by the American Diabetes Association and the European Association for the Study of Diabetes does not specifically address diarrhea, it emphasizes the importance of individualized care and consideration of potential side effects of medications, including metformin 5.