Medications That Treat Constipation and IBS-C

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In the past, prescription medications for treating chronic constipation and constipation-predominant irritable bowel syndrome (IBS-C) were quite limited. Fortunately, new medication options have become available while others are in the process of being tested for safety. Here you will find an overview of the current medications that are available by prescription for treating the problem of chronic constipation.

Amitiza (lubiprostone)

Amitiza is approved by the FDA for the treatment of IBS-C, as well as for chronic idiopathic constipation (CIC). Amitiza works by increasing the amount of fluids in the intestines and therefore easing the passage of stools. The medication works on a cellular level as it targets (activates) proteins involved in transporting chloride, thus Amitiza is known as a chloride channel activator. Most people who take Amitiza will experience symptom relief within 24 hours. You should not take Amitiza if you have a bowel obstruction, experience severe diarrhea or are pregnant or breastfeeding. Click here to learn more about Amitiza…


Lactulose, an osmotic laxative sold under a variety of brand names, including Cephulac, Chronulac, Constilac, Cholac, Constulose, Duphalac, Enulose, Generlac and Kristalose, is indicated for the treatment of constipation. Lactulose is a man-made sugar that is broken down by bacteria in the intestines, a process that pulls more water into the colon.

This increase in water softens, increases and normalizes the stool. The higher volume of stool helps to stimulate colon motility and therefore encourages a bowel movement. Lactulose is generally recommended to be used on a short-term basis .Lactulose is not typically a doctor's first choice as it is poorly tolerated (more bloating and gas) and is rarely more effective than other options.

 Before taking lactulose, make sure that your doctor knows if you are scheduled for surgery, suffer from diabetes, or are pregnant or breastfeeding. Click here to learn more about osmotic laxatives...

Linzess (linaclotide)

Linzess has been approved by the FDA for the treatment of IBS-C and CIC. In Europe, the medication is called Constella and is approved for the treatment of IBS-C. The medication is characterized as a guanylate cyclase-C agonist and is thought to work by increasing the amount of fluid in the large intestine resulting in increased number of bowel movements and decreased abdominal pain. Linzess is called Constella in Europe. Click here to learn more about Linzess...


Prucalopride is classified as a 5-HT agonist as it activates receptors for the neurotransmitter serotonin (5-HT). Unfortunately, prucalopride is not yet approved of for use by the FDA and thus is not available in the U.S. It is available in Europe and Canada, with some limitations on its prescription. Click here to learn more about prucalopride... 


Unlike the other medications profiled on this page, Miralax does not require a prescription. However, doctors frequently recommend Miralax due to its effectiveness in easing constipation.

Miralax draws water into the stool, softening it and inducing the urge for a bowel movement. Click here to learn more about Miralax...

Zelnorm (tegaserod)

Zelnorm is a medication that was designed to treat IBS-C and chronic idiopathic constipation (CIC), also works by increasing the amount of the neurotransmitter serotonin in the cells of the gut’s own nervous system. Unfortunately, due to identified serious health risks, the medication is now only available on an emergency basis and its prescription must be authorized directly by the FDA. Learn more about Zelnorm...

A Note About Antidepressants

Antidepressants are not approved as a treatment for constipation.

However, due to the high rate of depression in patients with IBS and due to the fact that antidepressants can have effective anti-pain properties, a doctor may prescribe an antidepressant to an individual who suffers from IBS-C. Those chosen for a person who suffers from constipation would be from the class called selective serotonin reuptake inhibitors (SSRIs), as they are less likely to be constipating. Examples of SSRIs include Celexa, Lexapro, Prozac, Paxil and Zoloft. Click here to learn more about antidepressants for IBS...


Ford, A., "American College of Gastroenterology Monograph on the Management of Irritable Bowel Syndrome and Chronic Idiopathic Constipation" American Journal of Gastroenterology 2014 109:S2-S26.

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