Yes, but exactly how long-standing diabetes and diarrhea are related is not clearly understood. About 10-20% of diabetics suffer from chronic diarrhea. Most people with diarrhea and diabetes have had diabetes for at least 10 years and show signs of nerve problems (neuropathy) by the time diarrhea develops. Other symptoms of neuropathy include dizziness when standing (postural hypotension), burning of the feet (peripheral neuropathy), or problems with urination.
Diabetes can affect the digestive system in many ways. Some people have “gastroparesis,” a condition in which food passes through the body slowly. This is caused by problems with the nerves that control the digestive system. Other people have incontinence of stool, diarrhea, or indigestion. It is not clear why some people develop diarrhea and other people develop other symptoms. Over 70% of people with diabetes develop at least one chronic problem with their digestive system.
The diarrhea linked to diabetes is often worst at night. It is not clear exactly how diabetes causes diarrhea. One theory is that more bacteria than normal grow in the intestines because food takes longer to pass through. This can also cause less fat to be absorbed, which can cause diarrhea. Bacteria can irritate the bowel wall, which causes it to secrete more fluid, resulting in diarrhea.
Diabetes can also cause the nerves that control digestion to stop working normally. These nerves help control the amount of water absorbed by the bowel wall. If the nerves don’t work properly, less water may be absorbed, resulting in diarrhea. Many people with diabetes have abnormal movements in their intestines, like gastroparesis. Sometimes these abnormal movements can cause food to be rushed through parts of the small intestine, which makes the diarrhea worse.
Another common but often-overlooked cause of diarrhea is dietetic food (processed for people on special diets). Many dietetic foods and candies contain artificial sweeteners like sorbitol, which can cause diarrhea by decreasing the amount of water absorbed in the intestines.
It is very important to make sure that other causes of diarrhea like infection or cancer are not to blame. Any new complaint of diarrhea should be reported to a doctor.