Key takeaways
Relistor (methylnaltrexone) and docusate (Colace) are both used to treat constipation, but they work in different ways and are used for different types of constipation. Relistor is an opioid antagonist that specifically treats constipation caused by opioid pain medications by blocking opioid receptors in the intestines. It is available only by prescription and comes in both oral and injectable forms. On the other hand, docusate is an over-the-counter stool softener that works by drawing water and fat into the stool to make it softer and easier to pass. Docusate is used for occasional constipation from hard, dry stools and comes in various oral forms, including capsules and liquid. Relistor can cause opioid withdrawal symptoms and is usually reserved for more severe cases of constipation, while docusate is generally safe for short-term use and is suitable for children. Additionally, Relistor is brand-name only and can be expensive, whereas docusate is available in generic forms and is more affordable.
