Medications, Diet Can Cause Constipation

Q:  I am a 77-year-old male who had a heart attack one year ago. My heart seems fine now, but since the heart attack, I have never had a normal bowel movement. I must take a laxative every day to stay regular. Sometimes I end up taking too much of the laxative and become sick for a day or two, but if I don't take enough, I become very uncomfortably constipated and bloated with gas.

I have had x-rays of my colon and stomach, and everything seems normal. I am taking several medications: docusate, senna, milk of magnesia, Ex-Lax, Maalox, fentanyl patch for pain, Avapro (irbesartan), atenolol, Amaryl (glimeprimide), and Lescol (fluvastatin).

Are the symptoms related to the heart attack? I do have a family history of constipation.

A:  I am glad you gave me your list of medications. From it, I know that you are treated for diabetes (as you taking a medication, Amaryl, which lowers blood sugar), I see that you are taking a medication (fentanyl) which very commonly causes constipation, and, I understand how bothersome your constipation must be, since you are taking five medications for your bowels (the first five of the list).

I do not think your constipation is due to your heart attack, although it may be related if your heart attack prompted a change in medications or a decrease in physical activity (which helps bowels move normally). Life stress plays a big role in bowel function, and in some cases, stresses (like a heart attack and recovery from it) lead to irritable bowel syndrome, where constipation alternates with loose stools, as you describe occurs to you sometimes.

I think you should make an appointment with your doctor to carefully discuss your constipation. Your doctor could then be sure that your constipation is not due to a medical illness (like hypothyroidism), see whether an alternative to fentanyl could be prescribed, check the control of your diabetes, which, when uncontrolled, can contribute to constipation, and discover how best to increase your physical activity.

You could visit a dietician and make sure you are getting enough fiber and water in your diet. After this evaluation, you and your doctor could look again at other medications that help with the common problem of constipation. For example, Ex-Lax and senna are similar medications, and may lose their laxative power if overused. There are many other medication choices that sometimes work better in the setting of long-standing constipation.

Julie L. Mitchell, MD, MS, is an Assistant Professor of Medicine at the Medical College of Wisconsin. She practices at the Froedtert & The Medical College of Wisconsin General Internal Medicine Clinic - East. Her column appears in the Milwaukee Journal-Sentinel.