Ask the doctors: Start addressing bowel problems with diet changes

Dear Doctors: I’m a 77-year-old man and was having trouble with hard stools. My doctor suggested a stool softener. It worked for about a week, but then I developed diarrhea. Over-the-counter diarrhea meds help only a little. It has now been three months. Lab tests are all normal. Any advice?

Dear Reader: Dealing with bowel problems is often a challenge. The fact that the treatment for the constipation issues you had been experiencing resulted in a swing to the other extreme, which is diarrhea, is both frustrating and unpleasant. In our own practices, we approach these issues with a focus on diet and, if needed, medications.

When it comes to managing constipation, we begin with the advice to increase dietary fiber, soluble and insoluble. Soluble fiber, which dissolves during digestion and forms a gelatinous matrix, is found in fruits, vegetables, grains and legumes. It is particularly abundant in black beans, figs, apples, oatmeal, plums and prunes, chia and psyllium seeds and blackberries. Each of these contains insoluble fiber as well. Good sources of insoluble fiber include almonds, walnuts, raspberries, pears and strawberries. Unfortunately, most people in the U.S. don’t manage to reach the daily target of 20 and 30 grams per day, respectively.

If diet doesn’t help, we then turn to over-the-counter products like stool softeners or laxatives. Stool softeners, which are known as emollient laxatives, work by increasing the water and fat content in the feces. This softens the feces and makes it easier to pass. Laxatives, which are often referred to simply as laxatives, work by activating the muscles of the colon that push feces from the body. Each of these can cause a range of side effects, including diarrhea.

The same soluble fiber that helps constipation can also ease the symptoms of mild to moderate diarrhea. This type of fiber absorbs water in the digestive tract, which helps in the formation of firmer stool. Soluble fiber also slows the passage of stool through the colon. Insoluble fiber, by contrast, can actually speed the passage of food through the digestive tract. When someone has diarrhea, even a normal amount of insoluble fiber can act as an irritant and make the problem worse.

When diet doesn’t help, OTC anti-diarrhea medications become an option. They contain ingredients that decrease the flow of liquid to the gut, which allows for firmer stool. They also slow the movement of the gut, which gives more time for the absorption of liquid, again leading to firmer stool. However, these medications do not address the underlying cause of diarrhea.

With a duration of three months, you are now dealing with chronic diarrhea. It is a condition that should not be ignored. Chronic diarrhea can lead to potentially serious complications, such as dehydration and malnutrition, particularly in older adults. It can also signal an underlying health problem, which may not have been evident in the lab work that was done. We would want our own patients to alert us to this type of change to bowel habits. If you haven’t yet, please do get in touch with your doctor with an update.

Send your questions to askthedoctors@mednet.ucla.edu.