What Is Recommended for Chronic Constipation?

Bret A. Lashner, MD


June 22, 2011


I often see patients with complaints of "constipation." What is most effective to offer them and how much investigation is warranted?

Response from Bret A. Lashner, MD
Professor of Medicine, Cleveland Clinic, Cleveland, Ohio

Chronic constipation is a term that is defined by fewer than 3 bowel movements per week but patients often call "hard stools" constipation. Almost certainly, when a patient presents with complaints of constipation, the provider will instruct the patient to increase the amount of dietary fiber (fruits and vegetables) in his or her diet and add an osmotic laxative such as milk of magnesia. If symptoms are not relieved, then an evaluation may be in order.

First, a colonoscopy is necessary, especially if the patient is older than 50 years, to rule out a structural lesion as the cause of the change in bowel habits. 

Next, a colonic transit study could provide valuable information. This study involves the ingestion of radio-opaque markers followed by an abdominal x-ray on day 7. If the markers are gone, then it should be possible to treat the constipation with fiber supplements and osmotic laxatives, such as MiraLAX®. If the markers are still present, then anorectal disorders, Hirschsprung disease, or colonic inertia must be considered.

To better evaluate the anal musculature, anorectal manometry is very helpful. Such testing can identify pelvic floor dysfunction, seen almost exclusively in women, as the cause of constipation. Some of these disorders may be treated with biofeedback techniques.

Osmotic laxatives such as milk of magnesia, magnesium citrate, and MiraLAX® all are available over the counter and safe to take for long periods of time. These laxatives simply add fluid to the bowel movement, which facilitates timely passage. 

The stimulant laxatives, such as Dulcolax®, Ex-Lax®, Correctol®, and Senokot®, are not safe to take for long periods of time because the bowel becomes dependent on them.

Lubiprostone (Amitiza®) is approved for constipation-predominant irritable bowel syndrome (eg, constipation with abdominal pain). Lubiprostone is a type 2 chloride channel activator that stimulates fluid secretion into the bowel and accelerates transit time. Other approved medications include colchicine (used for treatment of gout) and misoprostol (a drug used to protect the lining of the stomach from aspirin and aspirin-like products).

Certainly, the very last resort for severe colonic inertia, when all else fails, is surgery to remove most of the colon. Such a drastic approach to chronic constipation is very rarely done.


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