Q: My stools are loose most of the time. Otherwise I feel fine. Could something in my diet or a medication be the reason?
A: That's a couple of my first considerations when patients have diarrhea. Let's start with some of the common dietary triggers.
Sugar, especially fructose. Sugars stimulate the gut to put out water and electrolytes, which loosen bowel movements. One of the biggest offenders is fructose, which is found naturally in fruits (such as peaches, pears, cherries and apples) or added to foods and drinks, such as applesauce, soda, and juice beverages.
Artificial sweeteners. To reduce calories, many foods, beverages, candies and gums contain sorbitol, mannitol and xylitol. These additives are often an unrecognized cause of diarrhea.
Dairy foods. They contain lactose. With lactose intolerance, your body can't break down the sugar lactose in dairy products like milk, yogurt and ice cream, because your gut does not produce enough of the intestinal enzyme lactase.
Gluten. Gluten is a protein found in wheat, barley, rye, beer and even salad dressings. People who are gluten-sensitive may have a hard time digesting gluten and get diarrhea as a result.
Fried or fatty foods. Some people have a hard time digesting creamy or fried foods. When fatty foods are not absorbed normally, they go to the colon, where they are broken down to fatty acids, causing the colon to secrete fluid and trigger diarrhea.
Caffeine. Caffeine speeds up the digestive system. It's found in coffee, tea, chocolate, many sodas and foods flavored with coffee or chocolate. If you are lactose intolerant, you might be wrongly blaming the caffeine in your coffee or tea when the milk or cream is the real offender.
Many medications list diarrhea as a side effect. The drugs that tend to cause it most often include:
--Antacids: acid blockers called proton pump inhibitors, and acid neutralizers containing magnesium.
--Antibiotics: disturb the natural bacterial balance in the lower intestine.
--Colchicine: prescribed to treat gout.
--Metformin: used to treat Type 2 diabetes. Usually the diarrhea gets better over time.
--SSRI antidepressants: examples include citalopram (Celexa), fluoxetine (Prozac) and sertraline (Zoloft).
I suggest keeping a journal to help identify what might the culprit. But if symptoms persist, make an appointment with your doctor to make sure something else isn't the problem.
(Howard LeWine, M.D., is an internist at Brigham and Women's Hospital in Boston and assistant professor at Harvard Medical School. For additional consumer health information, please visit www.health.harvard.edu.)