Do Bowel Movements Affect Blood Sugar?

When you think about the effects of diabetes, you most likely think about the pancreas and blood sugar. You may also be aware of the increased risk of heart disease and stroke.

But there is one system you might not be thinking about that can be affected by diabetes – the gastrointestinal (GI) system. Here is why diabetes may harm the GI system, some of the problems that may result from it, and how to treat any problems as they arise.

Relation between Diarrhea/Constipation and Blood Sugar

Do diarrhea and constipation cause low or high blood sugar? Not by themselves, but both can be a sign of damage from high blood sugar levels.

It’s estimated that 75 percent of those with diabetes will experience some form of gastrointestinal problem. This is usually related to enteropathy or damage to the large intestine. [1] Enteropathy is a type of neuropathy that damages the nerves of the internal organs. [2] Diabetic neuropathy itself is a complication of high blood sugar over time. When your blood sugar is high, the blood becomes corrosive to the nerves, and if not treated, it leads to nerve damage, which is called neuropathy. [3]

Since internal organs don’t have the same pain receptors as the hands and feet, the decreased sensations of standard neuropathy don’t apply to enteropathy. Instead, various symptoms begin because the damage to the nerves leaves the organs that do not receive automatic signals as well as before and thus cannot act as quickly.

Those misfiring nerves can either cause the large intestine to contract poorly or not at all. It may also let fluids through the large intestine too quickly constipation (from poor signals to contract), diarrhea (from letting fluids through too quickly), an alternating pattern of constipation and diarrhea, and fecal incontinence (from nerve damage leading to decreased sensation to have a bowel movement) are common results of this damage. These problems are more common in type 1 diabetics, although type 2 diabetics can also experience these symptoms. [4]

To further complicate the issue, many drugs used to treat diabetes, such as metformin, have GI side effects. [5] This can lead to a delay in treatment for the neuropathy because the diabetic mistakenly assumes the symptoms are the result of the medication.

Symptoms of Diabetic Gastroparesis

Gastroparesis is a condition in which food remains in the stomach after the time it should have moved to the small intestines. Gastroparesis in diabetics is a result of damage to the nerves that control the stomach muscles.

If the vagus nerve or the nerve cells that line the stomach are damaged, the stomach does not contract and cannot move anything inside it. [6] It is more common in women, and anywhere from 27 percent to 63 percent of diabetics will experience it at some period in their lives. [7]

Symptoms of gastroparesis include:

• Feeling full for a very long period of time after a meal
• Feeling full after only eating a small portion of a meal
• Nausea
• Vomiting
• Stomach bloating
• Upper abdominal pain
• Heartburn
• Loss of appetite [8]
• Weight loss
• Weight gain [9]

These symptoms can occur and reoccur over a period of time or may start and not end.

Food &Exercise Suggestions when Having Diabetic Diarrhea

If chronic diarrhea from diabetes is a problem for you, there are steps you can take to reduce it. These involve both food and exercise. (Before taking any of these steps, it is important to see your doctor to make sure your diarrhea is not from another serious medical condition.)

Steps to take with food:

• Eliminate your diet or reduce foods that are most likely to cause diarrhea. These include dairy products, [10] caffeinated foods and drinks (especially coffee), [11] spicy food, [12] sodas and carbonated beverages, and foods containing artificial sweeteners. [13]
• Get yourself checked for celiac disease. 6 percent of type 1 diabetics have celiac disease, and diarrhea is one of its symptoms. If tests reveal you have celiac disease, start a gluten-free diet. [14]
• Keep a food diary so you can better understand what foods cause you diarrhea.

Steps to take with exercise:

• Don’t run as a form of exercise. While the cause is not known, up to half of runners experience exercise-related diarrhea. [15]
• Likewise, abdominal crunches can cause diarrhea and should be avoided if this is a problem for you.
• Keep workouts mild. Strenuous exercise can bring on diarrhea.
• Wear loose-fitting clothing when you exercise to put less pressure on the abdomen. [16]

How to Cure Diabetic Diarrhea?

If the above steps with food and exercise don’t lessen your diarrhea, consult your doctor again. They may be able to recommend further treatments that will work in your situation. These may include:

• Increased insulin doses if the diarrhea is being caused by high blood sugar.
• Prescribe medications that reduce diarrhea, such as loperamide, cholestyramine, or antispasmodic agents (drugs that reduce the activity of the smooth muscles of the intestine. [17] Probiotics, drugs that encourage the growth of healthy bacteria in the gut, may also be used. [18]
• Taking you off medications that might increase your chance of diarrhea, like metformin.
• In severe cases, surgery may be called for to determine if there is anything else wrong with the large intestine.

FAQ

What Causes People with Diabetes to Get Diarrhea?

High blood sugar can cause damage to the nerves in the stomach and intestines, so food is not as easily digested. When fluids and solids pass through the intestines, they do not contract as needed and cause diarrhea in the person.

Does Insulin Cause Constipation?

Poor control of blood sugar over a long period of time can lead to constipation from nerve damage, but regular use of insulin does not cause constipation.

Does Pooping Lower My Blood Sugar?

Bowel movements do not lower blood sugar. But if surgery has been done to shorten the intestinal tract, blood sugar can lower at the same time as a bowel movement. This is incidental and not caused by the movement itself.

Can Diarrhea be a Sign of Diabetes?

Diarrhea can be a complication of diabetes, but it is usually one that occurs later in the disease progression; it is not typically the first sign. So if you have chronic diarrhea, there could be several causes, but diabetes is most likely not one of them.

Final Thoughts

Digestive problems are a fairly common complication of diabetes but not one that is frequently talked about. Fortunately, there are ways to deal with them, including managing blood sugar so that those complications never have the chance to develop. If that cannot be done, changes in food, exercise, and medications can help with the problem.

References

1. Maisey, A. (2016). A Practical Approach to Gastrointestinal Complications of Diabetes. Diabetes Therapy, 7(3), 379–386. https://doi.org/10.1007/s13300-016-0182-y
2. National Institute of Diabetes and Digestive and Kidney Diseases. (2019, December 11). Autonomic Neuropathy | NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/nerve-damage-diabetic-neuropathies/autonomic-neuropathy
3. What Is Diabetic Neuropathy? | NIDDK. (2018, February). National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/nerve-damage-diabetic-neuropathies/what-is-diabetic-neuropathy
4. Maisey, A. (2016). A Practical Approach to Gastrointestinal Complications of Diabetes. Diabetes Therapy, 7(3), 379–386. https://doi.org/10.1007/s13300-016-0182-y
5. Drugs.com. (2018). Metformin Side Effects. Drugs.com; Drugs.com. https://www.drugs.com/sfx/metformin-side-effects.html
6. National Institute of Diabetes and Digestive and Kidney Diseases. (2019, November 21). Symptoms & Causes of Gastroparesis | NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/digestive-diseases/gastroparesis/symptoms-causes
7. Maisey, A. (2016). A Practical Approach to Gastrointestinal Complications of Diabetes. Diabetes Therapy, 7(3), 379–386. https://doi.org/10.1007/s13300-016-0182-y
8. National Institute of Diabetes and Digestive and Kidney Diseases. (2019, November 21). Symptoms & Causes of Gastroparesis | NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/digestive-diseases/gastroparesis/symptoms-causes
9. Maisey, A. (2016). A Practical Approach to Gastrointestinal Complications of Diabetes. Diabetes Therapy, 7(3), 379–386. https://doi.org/10.1007/s13300-016-0182-y
10. Di Costanzo, M., & Berni Canani, R. (2018). Lactose Intolerance: Common Misunderstandings. Annals of Nutrition and Metabolism, 73(Suppl. 4), 30–37. https://doi.org/10.1159/000493669
11. Iriondo-DeHond, A., Uranga, J. A., del Castillo, M. D., & Abalo, R. (2020). Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain–Gut Axis. Nutrients, 13(1). https://doi.org/10.3390/nu13010088
12. Esmaillzadeh, A. (2013). Consumption of spicy foods and the prevalence of irritable bowel syndrome. World Journal of Gastroenterology, 19(38), 6465. https://doi.org/10.3748/wjg.v19.i38.6465
13. Spencer, M., Gupta, A., Dam, L. V., Shannon, C., Menees, S., & Chey, W. D. (2016). Artificial Sweeteners: A Systematic Review and Primer for Gastroenterologists. Journal of Neurogastroenterology and Motility, 22(2), 168–180. https://doi.org/10.5056/jnm15206
14. Diabetes and Celiac Disease. (n.d.). Celiac Disease Foundation. https://celiac.org/about-celiac-disease/related-conditions/diabetes-and-celiac-disease/
15. Swain, R. A. (1994). Exercise-induced diarrhea: when to wonder. Medicine and Science in Sports and Exercise, 26(5), 523–526. https://pubmed.ncbi.nlm.nih.gov/8007797/
16. de Oliveira, E. P., & Burini, R. C. (2009). The impact of physical exercise on the gastrointestinal tract. Current Opinion in Clinical Nutrition and Metabolic Care, 12(5), 533–538. https://doi.org/10.1097/mco.0b013e32832e6776
17. Lee, K. J. (2015). Pharmacologic Agents for Chronic Diarrhea. Intestinal Research, 13(4), 306–312. https://doi.org/10.5217/ir.2015.13.4.306
18. Information, N. C. for B., Pike, U. S. N. L. of M. 8600 R., MD, B., & Usa, 20894. (2019). Can probiotics help against diarrhea? In www.ncbi.nlm.nih.gov. Institute for Quality and Efficiency in Health Care (IQWiG). https://www.ncbi.nlm.nih.gov/books/NBK373095/